Friday
June 13, 1986
                    OQ5~
Part If
 Environmental

 Protection  Agency

 40 CFR Parts 261, 271y and 302
 Hazardous Waste Management System;
 Identification and Listing of Hazardous
 Waste; Notification Requirements;.
 Reportafole Quantity Adjustments;
 Proposed Rule      |

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                        Federal Register / Vol. 51. No. 114 / Friday. June 13, 1986 / Proposed Rules
    ENVIRONMENTAL PROTECTION
    40 CFR Parts 261,271, and 302
    [FRL 2940-6]
                       j
    Hazardous Waste Management
    System; Identification and Listing of
    Hazardous Waste; Notification
    Requirements; Reportable Quantity
    Adjustments; Proposed Rule

    AGENCY: Environmental Protection
    Agency (EPA).
    ACTION: Proposed rule.

    SUMMARY: The EPA is proposing to
    amend its hazardous waste
    identification regulations under Subtitle
    C of the Resource Conservation and
    Recovery Act (RCRA) by expanding the
   Toxicity Characteristic to include
   additional chemicals and by introducing
   a new extraction procedure to be used
   in the Toxicity Characteristic. EPA is
   also proposing to incorporate the
   changes made pursuant to this rule into
   the lists of hazardous substances under
   the Comprehensive Environmental
   Response, Compensation, and Liability
   Act (CERCLA)  of 1980. Today's action is
   necessary both to define further the
   scope of the hazardous waste
   regulations and to meet a specific •
   mandate of the Hazardous and Solid
   Waste Amendments of 1984 (HSWA).
   This amendment will bring additional
   wastes under regulatory control,
   providing for further protection of public
   health and the environment.
   DATES: Comments on this proposed rule
  must be submitted on or before August
  32,1986. A public hearing has been
  scheduled for July 14,1986 at 9:30 a.m.,
  in Washington DC. Requests to present
  oral testimony must be received 10 days
  before each public hearing.
  ADDRESSES: One original  and three
  copies of all comments on this proposed
.  rule, identified by the docket number F-
  86-TC-FFFFF, should be sent to the
  following address: EPA RCRA Docket
  (S-212), U.S. Environmental Protection
  Agency (WH-562), 401 M  Street SW.,
  Washington DC 20460. The EPA RCRA "
  docket is located in the sub-basement
  area at the above address, and is open
  from 9:30 a.m. to 3:30 p.m., Monday
  through Friday, excluding  Federal
  holidays. To review docket materials,
  the public must make an appointment by
  calling Mia Zmud at 475-9327 orlCate
  Blow at 382^675. A maximum of 50
  pages of material may be copied from
  any one regulatory docket at no cost.
 Additional copies cost $.20/page.
 Documents identified in Section IX of
 the Supplementary Information section
   of this preamble are available in the
   docket. The public hearing will be held
   on July 14,1986 at the following location
   Vista International Hotel, 1400 M Street,
   NW., Washington, DC 20460. The
   hearing will begin at 9:30 a.m., with
   registration at 9:00 a,m., and will run
   until 4:00 p.m. unless concluded earlier.
   Anyone wishing to make a statement at
   the hearing should notify, in writing, Ms.
   Geraldine Wyer, Public Participation
   Officer, Office of Solid Waste (WH-
   562), U.S. Environmental Protection
'..  Agency, 401M Street, SW., Washington;
 ,  DC 20460. Persons wishing to make oral
   presentations must restrict them to 15
   minutes and are encouraged to have••'
   Written copies of their complete
   comments for inclusion in the official
   record.
   FOR FURTHER INFORMATION CONTACT:
  For general information contact the
  RCRA Hotline, Office of Solid Waste
  (WH-562), U.S. Environmental
  Protection Agency, 401 M Street, SW.,
  Washington, DC 20460, (800) 424-9346
  toll-free or (202) 382-3000.
    For information on specific aspects of
  this proposed rule contact: Todd A.
 Kimmell, Office of Solid Waste  (WH-
 562B), U.S. Environmental Protection
 Agency, 401 M Street, SW., Washington
 DC 20460, (202) 382-4770.
 SUPPLEMENTARY INFORMATION:
 I. Background
 II. Development of Toxicity Characteristic
   A. Introduction
   B. Chronic Toxicity Reference Levels   '
  • C. Dilution/Attenuation' Factor
   D. Proposed Toxicants and Regulatory
    Levels
   E. Analytical Constraints
 III. Development of the Leaching Procedure
   A. Introduction
   B. Objectives     '             '
   C. Disposal Environment and Model
   D. Leaching Procedure
   E. Leaching Procedure Issues
 IV. Other Aspects of Proposal         -
   A. Testing Frequency and Recordkeeping
   B. Relationship to Multiple EP and Oilv
    Waste EP  °                    •  '  .
 ,  C. Analytical Methods           «
   D. Notification Requirements
V. Relationship to Other Regulatory
    Authorities                ,  •
VI. State Authority        . '  ' ',  ' '  " i  •
   A. Applicability of Rules in Authorized
    States   ' ..'     ','.,'.  '  ..
   B. Effect on State Authorizations
VII. Economic and Regulatory Impacts '
   A. Regulatory Impact Analysis
  B. Regulatory Flexibility»Act
   C. Paperwork Reduction Act
VIH. Additional Information
  A. Chronic Toxicity Reference Levels
  B. Ground Water Transport Equation
  C. Tables or Proposed Contaminants and
    Data Used to Develop Regulatory Levels
  D. Development and Evaluation of the
    TCLP .        -        ,   ...-•-..
IX. References                .
   I. Background

     Under section 3001 of the Resource
   Conservation and Recovery Act
   (RCRA), EPA was charged with
   identifying those wastes .which pose a
   hazard to human health and the
   environment if improperly managed. It
   further called on EPA to identify such
   wastes through development of lists of
   hazardous waste and through       . ''
   characteristics of hazardous wastes,.'..','•
   These two means of identifying
   hazardous wastes employ
   fundamentally .different approaches.
   - To list a waste as hazardous, EPA
   conducts a detailed industry study,
 •  placing particular emphasis on the
   hazardous constituents contained in
   specific wastes from the industry being
   studied (See 40 CFR 261.11(a)(3}). This
   process involves literature reviews,   •
   engineering analyses, surveys and
  questionnaires, and site visits, including
  sampling and analysis of wastes. As
  such, the listing process may require
  from 1 to 3 years or more, depending on
  the complexity of the industry being
  investigated.
    The process of identifying wastes as
  "hazardous" by reason of a
 • characteristic is fundamentally different.
  Characteristics are those properties1
  which, if exhibited by a waste, identify
  the Waste as a hazardous waste. It is a
 generic process whereby EPA identifies
 properties that'might be possessed by a
 waste Which would cause the waste, if
 'improperly managed, to 'cause harm to
 human health Or the environment. The
 Agency then determines a reasonable
 mechanism by which such harm might
 occur; develops a  quantitative model-to
 identify hazard levels/and whenever
 possible, test methods for use in'
 determining if a. specific waste
 possesses hazardous levels of the
 property. Once EPA promulgates a
 characteristic it becomes self
 implementing. Any solid waste which
 exhibits the characteristic is a
 hazardous waste, and when treated so
 that it no longer exhibits the          ,
 characteristic, is:no longer subject to
 RCRA regulation'as a hazardous waste.;
   •Solid-wastes which do not exhibit'a
 characteristic, however, are riot
 necessarily non-hazardous.    ..'•'••'''••
 Characteristics are established at' levels ;
 at which there is a high degree of
 certainty that a waste which exhibits
 these properties needs to be managed in
 a controlled manner (Lei, is a hazardous
 waste). The Agency realizes that not all
 wastes which exhibit properties at
 levels below trie characteristic are safe,
 for disposal as nonhazardous waste. '
The Agency may therefore, upon

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                    Federal Register./ Vol. 51. -No. 114./ Frj^^e^
                                                                                                               21649
evaluation of specific wastes,from
specific industries, decide to list such
wastes as hazardous based on the
criteria defined in 40 CFR 261.11 (a) (3).
This reflects the Agency's philosophy,
first articulated in May'of I960, that the
characteristics define broad classes of
wastes that are clearly hazardous, whil,e
 the listing process defines .somp wastes
 that may pass the characteristic, but are .
 nonetheless hazardous wastes (45 FR
 ssiiij:" ;   .'   '"•''''' '.   ""'.''.  . •"•'   . .'
   In carrying out the RCRA mandate,
 EPA identified a number of   . ,
 characteristics which, if exhibited by .a
 waste, would indicate that the waste is
 a hazardous waste and shoulcThe „
 managed as such. One of these  ;     .
 characteristics, the Extraction Procedure
 (EP) Toxicity Characteristic (EPTC) (40
 CFR 261.24), was intended to identify
 wastes  which pose a hazard due to their
 potential to leach significant       .
 concentrations of specific toxic species.
   The EPTC'is the only characteristic
 which directly relates to,  the toxicity of a
 waste. This characteristic ehtaijs use of
 'jBi leaching test, the EP, which is.used in
 determining if an unacceptabry.high
 level of ground water contamination
 might result from imprpper.waste
 management. The EP results in a liquid
 extract which is analyzed for eight
 .metals  (arsenic, barium,  cadmium,
  chromium, lead, mercury, selenium; and ^
  silver), four insecticides  (endrin,
  lindane, methoxychlor and toxaphene),"
  and two herbicides (2,4-D and 2,4,5-TP).
  Regulatory thresholds were established
  for these 14 species .taking into account
  the attenuation and dilution expected to
  occur during migration of the leachate to
  the ground water, through use of a
  generic dilution/attenuation factor of.
  100(Ref.26).                  ".,      •
' '  At the time of promulgation,. EPA
  recognized two major shortcomings of
   the EPTC. The first was that the only :
  benchmarks for establishing toxicity
   levels  of specific chemicals, which were
   both.scientificaliy recognized and which
   addressed chronic exposure, were the
   National Interim Primary Drinking
   Water Standards (DWS). The Agency
   considered incorporating other    _,
   standards, such as the. Water Quality
   Criteria that were being developed
   under the Clean Water  Act. Preliminary
   drafts of these criteria, however,
   received substantial .negative comment
   from the scientific community. The
   Agency thus put off expansion of the
   EPTC pending development of
   acceptable standards. The second
   shortcoming was that.the EP was
   opHmized.Jp evaluate the leaching of
   elemental rather than organic
 constituents. Hence, the leaching of
 organics needed to be investigated.'  \  ;
 "."in addition to, addressing Ihfcleaching
 ;of organics, EPA believes that other
 aspects of the' EPTC can be improved.
 For example, ground water modeling   ;
 and knowledge of leaching and fate and
 transport mechanisms have advanced to
 the point that mathematical models can
 be used to identify species-specific
 dilution/attenuation factors, rather ;than
 relying on the generic 100 times level
 now employed in the EPTC. Also, the EP
 protocol is known to suffer a number of.
 operational shortcomings that,  while not
 critical, warrant attention. These
 shortcomings and their solutions are
 detailed in further sections,of this
 preamble.          ".         •
    Congress also.recognized the
 shortcomings of the EPTC, and amended
 RGRA in 1984 (section 3001 (g) and (h)},
 directing EPA to make" changes iri the EP
 to insure .that It accurately predicts
 leaching potential, and to identify
 additional characteristics" of hazardous
 waste, including measures orindicators
 of toxieity. EPA intends to. address both
 of these.mandates through expansion of
 the EPTG to include additional    -
 chemicals, and through the introduction
 of an improyed;leaching test to replace
 the current EP protocol.  ,     ^   .
    EPA is also planning to add another
 facet to the hazardous waste
_ characteristics. Specifically, EPA is
 working on a mechanism by which to
 identify wastes as hazardous by virtue
  of their ability to mobilize other
 . toxicants. This component would ,
  primarily affect solvent-coritairtirig
  wastes, and will  complement a
  regulation EPA promulgated oil   •'.  .
  December 31,1985 that redefined the
 , universe of solvents considered listed
  hazardous wastes to include certain
  solvent mixtures (50 FR 53315}. EPA   .
  indicated that this was an interim   .^
  measure which would be modified or
  superseded when further work! was   U ,
  completed. More detail regarding the
.  approach the Agency is considering is
  provided in  section II(E).
    " EPA is today proposing to amend the
• Extraction Procedure Toxicity
  Characteristic by (l) expanding the
  characteristic to include 38 additional  -
  compounds,  (2) applying compound-
   specific dilution/attenuation  factors
  generated from a ground water transport
   model, and (3J introducing a-second
   generation leaching procedure, the
   Toxicity Characteristic Leaching
   Procedure (TCLP), that has been
   developed to address the.mobility of
   both .organic and'inorganic compounds,
   and to solve the operational problems of
   the EP protocol.
  It is important to point put that while' .
this proposed rule fulfills tfie  " -"'    ;T~
Congressional mandate'to add
additional characteristics of hazardous
waste, considerably more work is now.
underway within EPA to look at  .
additional constituents that could and. .
should be added to the proposed rule,
and to explore other characteristics that-
will deal with.toxicity,c.i
   On January 14,1986 (51.FR 1602), the:
Agency proposed the framework, for a
.regulatory-program to implement the
congressionally mandated land disposal
prohibitions. The action proposed
procedures to'establish treatment
 standards for hazardous waste and
 procedures by which EPA will
 determine whether to allow continued •""
 land disposal of specific hazardous
 wastes.    . ,j .,,-/    ,  ' •  '  -••-".. • -j
   In implementing these; proeeduresvthe
 Agency ha,s'|aro'posed to enlploy the   /;
 TTCtP .to.estimate the leaching hazard ,'
 posed'by wa ste placed, in Subtitle C
 facilities. The'safne subsurface"trahspprt
 model' is used in bbth.the land disposal
 regulation land this proposed.jregulation.
 However,'minormodifications'to ".; .,
 account for'disposal/in'a non-Kazardpus
 versus a haziardous waste landfill have
 been made in the, transport equation for
 use in this  proposed rule. In addition,
 different risk levels are used to establish
 the regulatoiry level for carcinogens, and
 a different confidence, interval for the
 ground wat«r transport simulation is
 used to establish the dilution/
 attenuation factors, Howeveri to the
 extent that commenters have provided
 us with their views on the model either
 in the context of the land disposal   •
 restrictionsprogram-or it.s delistihg
 programs,  tliose comments need only be
, referenced in response to this proposed
  rule. More information on the  •     •  .
  differences between the models is
  provided to Section V of this preamble.'

  il. Development to Toxicity•;....,;
" .Characteristic,   .'

  A. Introduction                    ,
    In establishing a scientifically
  justifiable £ipproach for arriving at
 "threshold  concentrations, EPA wanted
  to assure  a high degree, of confidence
  that a waste, which releases toxicants at
  concentrations above the regulatory
  threshold level would pose a ha,zard to:
  human health.   •
     The existing EPTC uses the National •
  Interim Primary Drinking Water    ' .• •*
   Standards [DWSJ as toxicity thresholds
   for individual pollutants, and combines
   these with a generic dilution/
   attenuation factor (100 timesJUo. yield  -
  •the regulatory threshold. The-new-  •'••'

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   21650
Federal Register / Vol. 51, No. 114 / Friday, June 13,~1986 A Proposed Rules.
  approach, described below, uses chronic
  toxicily reference levels, combined with
  a compound-specific dilution/
  attenuation factor [derived from
  application of a ground water transport
  equation), to calculate the regulatory
  level concentrations for individual
  toxicants.

  n. Chronic Toxicity Reference levels
    Implementation of the Toxicity
  Characteristic level setting approach  - ,
  described below, requires the initial
  input of a toxicity limit to establish a
  regulatory level for each contarnjnant.
  Limits set for protection against chronic
  toxicily effects are the reference
  standard of choice since this level will
  usually be protective for both chronic
  and acute effects. The first step in-
  developing regulatory levels is therefore
  the development of a measure of
  "acceptable" chronic exposure for
  individual toxicants in drinking water.
    EPA, under other statutory mandates,
  has investigated the adverse health
  effects due to specific chemicals with a
  view toward controlling exposure
  through different media. Human health
  criteria and standards have been
  proposed or promulgated for certain
  substances in particular media. Since
  these have received Agency and public
  review and evaluation, EPA is  proposing
  to use such standards as the starting
 point for the back calculation model,   ~
 where such standards are available.
 EPA used the DWS for the 8 elements
 and 6 pesticides as the basis of the
 Extraction Procedure Toxicity
 Characteristic.
   Drinking water standards are based
 upon toxicity, treatment technologies,
 costs, and other feasibility factors such
 as availablity of analytical methods. In
 developing DWS's, the intital step is the
 identification of non-enforceable health
 limits. The assessment process for
 establishing these health goals includes
 evaluation of the quality and weight-of-
 evidence of supporting lexicological
 studies, absorption rates of specific
 toxicants, the possibility that a
 compound or element is nutritionally
 essential at certain levels, route of
 exposure, and exposure medium
 apportionment.
  For non-carcinogens, these health
 limits are denoted as Reference Doses
 (RfD's). The RfD is an estimate of the
 daily dose of a substance which will
 result in no adverse effect even after a»
 lifetime of such exposure. It is thus a
 chronic toxicity limit. The  establishment
of a chronic toxicity reference level for
carcinogens requires setting a specific
risk level which is then used to calculate
the Risk Specific Dose (RSD). The RSD
is the daily dose of a.carcinogen over a
                    lifetime which will result in an incidence
                    of cancer equal to the specific risk level.
                    An RSD established at the 10"5 risk
                    level translates.to a probability of-one in
                    one hundred thousand that an individual
                    might contract some form of cancer in
                    his or her lifetime.
                     In developing toxicity levels for
                    carcinogens, EPA is further proposing a
                    weight'-of-evidence approach which
                    involves categorizing carcinogens
                •   -according to the quality and adequacy  "
                    of the supporting lexicological studies.
                   This approach was proposed by EPA in
                   its Carcinogen Risk Assessment
                   guidelines published in the Federal
                   Register on November 23,1984 (49 FR
                   46294).                    '.-....
                     In order to account for toxicant    /
                   exposure from other sources (i.e., air
                   and food), EPA is also proposing to.limit
                   the RfD value to some fraction, as is
                   done in developing drinking water
                   standards. The fraction of the toxicity
                   level used iri-these standards is
                   compound-specific, and is apportioned
                   according to exposure assessment data,
                   if adequate data exist, or by use of an
                   arbitrary value of 20 percent if adequate
                   exposure assessment data do not exist.  .
                   EPA is proposing a similar approach for
                   the Toxicity Characteristic.
                    Note, however, that EPA is. not
                   proposing this approach for the
                .   carcinogens, as it appears that a small
                   reduction in the RSD would still be well
                   within the margin of uncertainty of the   '
                   estimated RSD. Rather, EPA is
                  proposing to use 100 percent  of the RSD
                  value. Section VIII(A) of this preamble
                  provides detailed information as to the
                  identification of chronic toxicity
                  reference levels.  '  .
                    One area that the Agency solicits
                  comment on is whether, as an
                  alternative to using the DWS's, the
                  Agency should consider using the RfD or
                  RSD values as the starting point for. the.
                  Hack calculation model, even when
                  DWS's are available.

                  C. Dilution/Attenuation Factor

                    After a toxicity level has been
                  identified, the degree of kttenuation and
                  dilution that a compound is expected to
                  undergo during transport through the
                  ground water to an underground
                  drinking water source is determined.
                 The ground-water transport equation
                 EPA is intending to use to estimate
                 dilution and attenuation, estimates the
                 reduction in toxicant concentration that
                .would occur as toxicants are
                 transported in ground water over a
                 specified distance from the disposal unit
                 to the point of exposure (i.e., drinking
                 water well), as depicted in the following
                .figure (Figure 1):

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                            t Register/ Voisi.Np. 114 / Friday, June 13,1986 / firoposect Rules
                                                                       21651
              Fiqure
                      Ir  Illustration of,Dilution/Attenuation
                  TAT.
     Saturated
       Zone
                         Dilution/Attenuation
                          .Occurring During.,-
                            Migration of
                            Contaminant
                              To  Well
                                                                 n
                                                                   Drinking
                                                                    Water .
                                                                     well
                                                               IB]
       (At  Refers  to the concentration  of,t'he  contaminant  in the
           laachate  at the  bottom of  the disposal Unit.      .    .

       [Bl  Refers  to the concentration  of the  contaminant, in the  -
           drinking  water well, which is calculated using  a ground
           water transport  equation,  and is expected to  be lower
           than the  concentration at  (A) due  to attenuation and
           dilution.      -      . ,                  ,       .  '     .
  This equation relies on compound
  specific hydrolysis and soil absorption
  data, coupled'with parameters      ;
  describing a generic underground
  environment (e.g.; ground water flow
  rate, soil porosity, ground water pHJ, to
  calculate the degree of attenuation and
  dilution a compound would be expected
  to undergo as it migrates to.an
  underground drinking water source.
''. Values for environmental parameters
 /"have been selected based on review of
  subsurface geological conditions at
  existing landfills across the continental
  United States. Boundary conditions and
  interrelationships between the above
  parameters have been established based
  on a sensitivity and an uncertainty
  analysis.
     Originally, EPA had also hoped to
   develop dilution/attenuation factors for
   metal species through use of a second
   model* since these species.generally
   behave differently in the ground water
   environment,than do the .organic
 .compounds. Unfortunately, this model
 could not be fully developed in time for
 today's proposal; Accordingly, while
 EPA is continuing to work on modeling
 • metal transport, EPA is retaining the ,_
 present EP Toxicity Characteristic levels
 for the elemental toxicants. .
   Details pf the ground water transport
 equation to be used for organic     •
 compounds are provided in section
 VIII(B). Note that in the Federal Register
 of January 14,1986, the Agency
 proposed to use the same basic ground
 water transport equation for use in the
 Land Disposal Restrictions Rule (51 FR
 1602). The proposed Land Disposal
 Restrictions Rule equation, however,
" contains minor .differences to account
 for the additional engineering controls
  (e.g., landfill caps), required of Subtitle
  C hazardous waste facilities, and the
  higher standard of confidence required
 • under HSWA for determining that a
  hazardous waste is suitable for land
  disposal. As noted previously, different
 risk levels are used;"to establish the  '
 characteristic regulatory threshold for'1
 carcinogeriSi'arid a different'confidence
.interval is used for the ground water
 transport simulation to establish the
 dilution/attenuation factors. While
• section VIH(B) provides additional'." . '
 information concerning the equation .
 proposed for use in the Toxicity
 Characteristic, considerably more detail
 concerning/this equation is provided in
 the preamble .section to the proposed
 Land Disposal Restrictions Rule (51 FR
 1602, January 14,1986).              .
    Since many aspects of the ground
 water transport equatioa are similar
 between the two rules:, cqmrnenters
 need not repeat relevant comments that
 have already been made in response to
 the LandDisposal Restrictions Rule. .
 These earlier comments may be
 referenced; although aB relevant    .
  comments, will be considered in .-..;. v
  developing the Toxicity Characteristic   .
 final rule. Comment specific;to EPA's-,
  use of the.pquation for this rule, should
  howeverv.be submitted
  DrPFOposed Toxicants tin'd Regulatory
  Levels    t, •• •.     • -  -  .".'..   ..'..'   ['
    In order'toiestabiish a Toxicity .;. -
  Characteristic regulatory level for.... ^
  Individual Compounds, adequate and
  verified deita must exist for EPA to (1)
  identify a toxicit'y level (i.e., DWS, RfD,
 •- or RSDJ, and (2)  calculate a dilution/
  attenuation factor through application of
  the ground water transport equation. As
  discussed previously, EPA will retain
  the 100 times factor used in the current
  EP Toxicity Characteristic for the
  elemental drinking water toxicants. Due
  to the Ageincy's continuing efforts'tp
  develop'an adequate ground water
  transport_equation for the metals,
   addition of elemental and anionic
   toxicants to tlie Toxicity Characteristic
 !.  is being delayed. The Agency expects to
   propose Toxicity Chara'cteristic
   threshold* for nickel and thallium 'during
   the-period between proposal and
   promulgation of this rule.
     In selecting additional organic
   toxicants-to incorporate in today's
   proposal;the'Agency identified those
   Appendix VIII compounds for which
   there existed a promulgated or proposed
   drinking" water standard, or an RfD or
   RSD. The compounds identified as a .-.. *
   result of these efforts were then
    examined to determine if adequate fate -
    and transiport data were available to
  .' establish a compound-specific dilution/
    attenuation factor.            x

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   21652
                        Federal Register / Vol. 51. No. 114 / Fridav< Iune
     These efforts have resulted in the
   identification of a total of 52 compounds
   for the Toxicity Characteristic. This
   includes the existing 14 EPTC
   compounds, and 38 compounds whose
   thresholds are driven by their toxicity,
   as shown in the following table (Table

   TABLE 1: PROPOSED TOXICITY CHARACTERIS-
    TIC CONTAMINANTS  AND  REGULATORY LEV-
    ELS
HWNO
D0ie,._
D004 ,„„„.,„
D005,™_ ,.,...
D010,, 	
D020,,.™™,.
0006, 	 „_„
D02I 	 , 	
0023 HZZT
D024 	
0025 „.„___„
O007,,,,™,..™.
D026..™.,..™.
D027 	 	 _
D028. 	 „„
DOI6 	 „.,
D029,, 	 .^.^
O030,.«™,,,^,M
D03I 	 „„„..
0032,™., 	
0033 	 __
D034 .'.'"'".'I

0035u,.w..HHM,w
D038, 	

0037,...™,......
D038««™..,,.,,..M
DOOfl ,„..«..„..„
D013, 	 ™> 	
D009,MHM.,wm.
DossIZZIZ
D040 .-.„„, „
0041 	 	 „„.,.
D042,«.,««, .,„,.,
O043 ,„,„««,„„..
D044 =..„..„„,„„„
DO 10™,™, 	
D01 1 ,w.M«,,w.n.
D04S..WM,,,H,...,

0048 .„„.,„„.,„.

D04 7 » 	 .nm...
0048,..,™^,..,,.

0049lMltM^.il4,M,
. Contaminants
Aorytonilri* 	
Arsenic „.____ 	 .
Barktm 	 .„...„.«.„..„
Benzene 	 „.
Bis(2nenol...«M.,«w.m.......
"yridine ,„ 	 	 	 .......
cloroum..,.....,....^.,,...
fiver ...„..„..„„„„ .
.1.1.2-
Telraehloroethano.
.1A2-
Teuachloroetharte.
etracrHoroethylehe ..
3.4.6-
Teuachlorophenol
'okien«.™»^,...,._^
DOIS.,,.™.™.,.,,^ oxaphene... 	 „,...„
DCSO,,«mm«,,..««

D051 M™.™,,.,...

Dosa,.,.,,.™,,,,.,.
D053 ,...„,„„„„

D054,g,,..,.w,Mw^

0017,,™..,......,
DOSS ..,..„.„,„.,
1.1.1- •
Tncttkxoethano.
1.1.2-
Trichloroethane.
Trichloroeth)lone 	
2.4.5-
Tflchtorophenol.
2.4.8-
Tnchloroptienol.
2,4,5-TP(S«vex). 	
Wnjrl eh(orido_ 	
( CASNO
.. 107-13-
.. 7440-38-
.. 7440-39-3
71-43-
111-44-4
7440-43-
75-15-0
56-23-
57-74-
108-90-
67-66-3
1333-82-
' 95-48-
108-39-
106-44-5
94-75-7
95-50-
106-46-7
107-06-2
75-35-4
121-14-2
72-20-8
76-44-2

118-74-1
87-68-3

67-72-1
78-83-1
7439-92-1
58-8S-9
7439-97-6
72-43-5
75-09-2
78-93-3
98-95-3
87-86-5
108-95-2
110-86-1
7782-49-2
7440-22-4
630-20-6

79-34-5

127-18-4
58-90-2

108-88-3
001-35-2
71-55-6

79-00-5

7S-01-6
95-95-4

88-06-2

93-76-5
75-01-4
Regula-
tory "
level
(mg/l)
5.0
5.0
100
0.07
0.05
1.0
14.4
0.07
0.03
1.4
0.07
5.0
10.0
10.0
10.0
1.4
-4.3
10.8
0.40
0.1
0.13
0.003
0.001

0.13
0.72

4.3
36
5.0
0.06
0.2
1.4
8.6
7.2
0.13
3.6
14.4
5.0
1,0
5.0
10.0

1.3'

0.1
1.5

I4.4
0.07
30

1.2

0.07
5.8

0.30

0.14
0,05
  There is one group of chemicals for
which the Agency considers use of the
health criteria/ground water transport
approach to setting threshold
concentrations as being inappropriate in
some cases. These are solvents.
Solvents need to be managed in a
controlled manner not only because of
   inherent toxicity, but also because they
   can mobilize hazardous constituents
   from codisposed non-hazardous waste.
   Since solvents exhibit this property, the
   Agency is working to identify such
   wastes through use of a solvent
   override.            •           ;
     The Agency intends to set regulatory'
   levels for solvents based, on the total
   amount of solvent observed in the TCLP
   extract. Thus, wastes whose TCLP
   extract caijtains more than g specified
   amount of total  solvent would be
   identified as a hazardous waste, even if
   none of the health criteria based
   thresholds for the individual solvents •
-   are exceeded. The Agency is also
   exploring the possibility of developing a
  solvent power test which would be
  designed to determine the actual ability
  ,of a waste  to mobilize hazardous
  constitutents for non-hazardous wastes!
  The Agency solicits ideas, data and
  comments on these and other       i
  approaches.
    The next section .presents a discussion
  regarding some of the analytical
  constraints EPA  faced in establishing
  regulatory levels. Section VIII(C)
  provides tables presenting each
  compound and the data  that EPA has
  used to calculate~the.regulatory level.
  EPA anticipates that the list of toxicants
  to be included in the Toxicity
'  Characteristic will be  periodically
  expanded as more information qn the
  Appendix VIII compounds is developed.
 E. Analytical Constraints
   As illustrated in Table 1 (and further
 in section VIII(C)), the regulatory levels
 for the proposed compounds span about
 5 orders of magnitude  (i.e., from the low
 parts per billion to 100 parts per million].
This is not so much a function of the
individual dilution/attenuation factors,
but rather due to  the great range in
toxicity levels of the individual
toxicants. Since many  of the toxicity
levels for the carcinogens (and some of
the non-carcinogensj (see section
VIII(A)) are very low, depending on the
magnitude of the dilution/attenuation
factor, the calculated level will also be
very low. This presents ~a problem for
the Agency since some of these
calculated thresholds are below the
analytical level measurable using
currently available methodology. This
affects 7 of the compounds (See section
VIII(C)).
   EPA believes that the appropriate
way to deal with this problem is to
establish technology based regulatory
levels.1 The lowest level that can be
   reliably achieved within specified limits
   of precision and, accuracy during routine
   laboratory operating condition's is the
   quantitation limit. The quantitation limit
  . thus represents the lowest level   •
   achievable by good laboratories within
   specified limits during routine
   laboratory operating conditions. The
   quantitation limit is determined through
   ihterlaboratory studies, such as
 .  performance evaluation studies.
     If data are unavailable from     :
   interlaboratory studies, quantitation
   limits are-estimated based upon the
   detection limits and an estimate of a
   higher level which would represent a
   practical and routinely achievable level
   with relatively high certainty that the
   reported value is reliable. EPA
   estimated this level to be 5 to 10 times
   the detection limit in their final rule on'
   National Interim Primary Drinking
   Water Standards for Volatile Synthetic
   Organic Chemicals (50 FR 46880,    '.
  November 13,1985). EPA believes that
  setting the  quantitation limit  at 5 times ,
  the detection limit is a fair expectation
  for most regulatory and commercial
  laboratories. Public comment is
  specifically requested on the  use of 5
  times the detection limit as a  general
  rule as to what levels can be  expected to
  be measured routinely by commercial
  laboratories with reliability.
    Use of either detection limits or
  quantitation limits would allow for
  regulatory levels that fall below the
  analytically measurable level to  be      '
  periodically updated as advances are
  made in analytical methodology. EPA is
  proposing the-use of the quantitation
  limits because the determination that" a •
  compound is present (in the extract
  above a specified value) conclusively
  demonstrates the presence of  a hazard.
  EPA is seeking comment, however, on
  both approaches.  -   .-1.           .
  . The tables in section VIII(C):indicate
  the quantitation limits for each of the    ^~
 elements and compounds, as well as the
 appropriate  EPA SW-846 analytical
 method numbers (Ref. 27). (Analytical.   •
  1 Such levels could be set at the analytical   •
detection limit or, as an alternative/they could be
set at the limits of accurate quantitation (i.e..
 quantitation limit). In general, EPA defines .tjie
 method detection limifas the minimum *    :
 concentration of a substance that can be-measured'
 and reported with 99 percent confidence thaUhe-
 true value is greater than zero. The specifications of
 such a.concentration are limited by the fact'that
 detection limits are a variable affected by the
. performance of a given measurement system.
 Detection limits are not necessarily .reproducible •
 over time in a given laboratory,.even when the same
 analytical procedures, instrumentation and sample
 matrix are used; Difference's between detection and
 quantitation limits are expected, since the detection
 limits represent the, lowest achievable level under
 ideal laboratory conditions, whereas the
 quantitation limit represents the lowest.'achievable'
 level under practical and routine laboratory
 conditions.'

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                    Federal Register / Vol. 51, No, 114 / Friday. June 13, 1986 /JPropWd Rules
                                                                       21653
 methods for the Tpxicity Characteristic
 compounds are discussed more fully in
 section IV(D) of this preamble.) The
 quantitation limits used; are based on
 the presence of these compounds in a
 water matrix. Since TGLP extracts
 would also be  aqueous in nature, EPA is
 proposing to use the quantitation limit
 as observed in water. EPA recognizes,
 however, that  while these;quantitation
 limits would be attainable for most,
 wastes, Qther.wastes will produce an
 extract that is  qualitatively different,
 and may not allow quantitation to the,
 same low level as water. This, however,
 will be waste specific and difficult to.
 predict beforehand. While specifying a
 higher quantitation limit is an option,
 EPA is reluctant to do so due to the
 degree of environmental protection that
 might be sacrificed. EPA is, however,
 working  to determine actual
 quantitation limits on real wastes, which
 may result in increases in the
 quantitation limit, and the
 corresponding regulatory level, for some
 of the contaminants. EPA solicits
 comments and suggestions on how to
 deal with this issue.      ,     .
    Three  of the .phenolic compounds that
 are included in today's proposal ortho-,
 meta-, and para-cresol, also pose an
 analytical problem. Specifically, meta-
 and para-cresol cannot be analytically
  separated using readily available
 ; techniques. In order to overcome this
  problem, and  given that these isomers
 , all act in an additive manner, the
  Agency, is proposing to establish a single
  level for total p-, m- and p-crespl.
    Public comment and information on
  all aspects of the issues presented in
  this section, are requested to assist EPA
  in making a final choice of analytical
  methods and  the specific performance
 - requirements in the final rule.   ,
  Supporting data/information is .
  requested for any comments provided.
  Specifically, public comment is
  requested on the following questions:
    • Are the proposed analytical  .
  methods technically and economically
  available (see section IV(D) of this
  preamble)?
    •  What is the precision/accuracy of
  the analytical methods at the proposed
  quantitation levels?
    •  Are there sufficient qualified
  laboratories capable of measuring at
  proposed quantitation levels?

  III. Development of the Leaching
  Procedure
-  A. 'Introduction          -
    The Extraction Procedurfi.(EP) was
  designed to simulate the leaching that '
  would result when a solid waste is co-
   disposed with municipal wastes in a
sanitary landfill. The EP was intended to
be a first order approximation of the
leaching action of the low molecular
weight carboxylic acids generated,in an
actively decomposing sanitary landfill.
Acetic acid, one of the more dominant  ;
carboxylic acids present  in municipal
waste leachate, is added to deionized
distilled water to make up the extracting
medium used in the EP. The acetic acid
models primarily the leaching of metals -
from an industrial waste. The impetus
' behind development of the Toxicity
Characteristic Leaching Procedure
(TCLP) was the need also to address the
leaching of organic compounds (Ref. 26).
   In addition, EPA believes that the EP
 protocol can be improved in certain
 areas. For example, the EP involves
 continual pH adjustment (titration) with
 0.5 ,N acetic acid to a pH of 5.0+0.2. This
 can involve more than 6  hours of
 operator attention and can be difficult
 for some waste types, particularly oily
 wastes. In developing the TCLP, EPA
 felt that elimination of ,the need for
' continual pH adjustment would be a
 desirable improvement. As another
 example, the EP involves separating the ,
 initial liquid from the solid phase of the
 waste,.,as well as separation of the
 liquid (extract) derived from the .  •
 leaching test. These steps, involving    ,
 pressure filtration through a 0145 um
 filter, can be difficult and time
 consuming for certain waste types, and
 warrant simplification. In addition, other
 minor changes in the EP protocol, such
 as shortening the duration of the test
 and accounting for the loss of waste
 materials to the side walls of s,ample
 containers, were felt to be of use in
 lowering the cost of the  test and
 improving the overall precision of the .
 method. Thus, the Agency believes that
 development of a second generation-
 extraction procedure was of value even
 if the EP were found to be acceptable for
 organics. -        ,       •
 B. Objectives           .,...-.'
   ,EPA's intent, then, was to develop  an
 improved leaching test method suitable,
  for use in evaluating wastes containing
  organic toxicants. It is important to note
  that the purpose of the EP, as well as
  this new method, is as a means of
  determining whether a waste, if
  mismanaged, has the potential to pose a
  significant hazard to human health or
•  the environment due to its propensity to
  leach toxic compounds^EPA believes
  that the EP adequately  accomplished
 . this goal for the currently regulated
  toxicants.          .               .
    When the EP was developed, the
  Agency had little empirical data upon
  which to base its assumptions regarding
  accuracy (Kef. 26). Hence, while the^ few
 data that were available>egarding, ,
 accuracy were used in developing the
 EP, it was primarily based oir what was
 reasonable, as well as what would
 provide a reproducible (precise) test  •
 protocol. While improved      -  •
 reproducibility is one objective of the
 TCLP, the major objective was to
 accurately model the mobility of
 constituents from wastes, particularly
 organic constituents. Other objectives
 were that the test be relatively
 inexpensive: to conduct; that, if possible,
 it yield an extract amenable to
 evaluation with biological toxicity tests;
 and that it also model, the mobility of
, inorganic species. This last objective
 would permit EPA to expand the toxicity
 characteristic to encompass organics,
 yet require only one leaching test for
 both organics and inorganics.        ,-

 C. Disposal En vironmen t and Model .

  • The specific environment modeled by
 bpth the current EP and the TCLP is co-
 disposal of industrial waste with refuse
 in a sanitary -landfill. The Agency's
 concern was that potentially hazardous
 waste, if not brought under the control
 of the RCRA hazardous: waste system,/
 might be se-nt to sanitary landfills, with
 a resulting high level of leaching      '
 activity. This concern, has not changed. -
 Although the Agency believes that fewer
 industrial solid wastes are .being
 disposed i'ri this manner as compared tb
 a few years ago, the Agency also
 believes that the co-disposal, scenario'
 still represents a reasonable worst-case.
 mismanagement scenario. In addition,
 the Agency believes that the predicted
 degree of contaminant migration,  as
 indicated by the TCLP, could reasonably
  occur in the course of other types of
 land management of wastes' (see section
          ''
              .
    Hence, the experiments used to
  develop the TCLP were set up to
  conform as closely as possible with the
  co-disposal model. Specific features of
  this model: were that the landfill is
  composed of 5 percent industrial solid
  waste and 95 percent municipal waste,
  and that the character of the leaching
  fluid that the waste will be exposed to is
  predominantly a. function of the
  decomposing refuse in the landfill. In
  expanding the Toxicity Characteristic,
  the modelis and assumptions used in
  developing the EP have been retained.

  D. Leaching Procedure

    The work undertaken to develop and
  evaluate the new leaching test was
  carried out in three phases, and
  involved 11  wastes and close to 100
  organic arid inorganic components
  which leached from these wastes.

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                      Federal Register / Vol. 51, No. 114 / Friday. June 13,1986 / Proposed Rules
  Briefly, the research involved leaching
  these wastes in a pilot-scale field
  facility with sanitary landfill leachate,
  measuring the concentration of the
  compounds which leached from the
  wastes, and attempting to duplicate
  these concentrations in a laboratory
  tost, the TCLP (Ref. 6 and 7).
    A TCLP has ben developed as a result
  of this work. EPA believes  that this test
  method is reasonably accurate in terms
  of modeling a field-scale co-disposal
  scenario for both organics and
  inorganics. In addition, it appears that
  many of the operational problems
  associated with the EP protocol have
  been overcome in the process of
  developing the TCLP. The test has also
  been subjected to ruggedness and
  precision  evaluations, and a limited
  multi-laboratory collaborative
  evaluation, and is currently being
  evaluated in a more comprehensive
  collaborative evaluation.
    Section VI1I(D) of this preamble
  providc-s detailed information with
  respect to the TCLP development and
  evaluation program. The regulation
  section provides the actual TCLP
  protocol, as Appendix II to Part 261. A
  more detailed discussion pertaining to
  the TCLP is provided in a background
  document  that EPA has prepared {Ref.
  33).

 R Leaching Procedure Issues          .
   In  an effort to identify and resolve any
 potential problems associated with the
 TCIJP prior to proposal, and also to
 inform the public of EPA's activities in
 this area, EPA held a number of
 meetings at which various aspects of the
 procedure  were reviewed and draft
 procedures circulated. These included
 public discussions at meetings of the
 Association of Official Analytical
 Chemists and the American  Society for
 Testing and Materials (ASTM).
  As a result of these meetings and as a
 result of the Agency's own efforts in
 these areas, a number of issues have
 been  identified and some minor changes
 to the TCLP protocol have also been
 made. Following is a discussion of these
 issues, and how they have been
 addressed in  the proposed TCLP.
 1. Overall Issues

  a. Accuracy of TCLP. As indicated
 previously, EPA was directed by the
 IISWA to make the EP more  accurate.
 EPA's experimental program to develop
 the TCLP was intended to provide an
 accurate extraction method, in terms of
ability to model a field  co-disposal
situation. One of the issues associated
with the TCLP is whether the method is
adequately  accurate in this respect.
    In an effort to better quantify how
  well the TCLP compares to the field
  model, the distributions of the actual
  and absolute percent differences
  between concentrations observed in the
  field model and those observed in the
  acetate buffer system chosen for the
  TCLP (see section VIII(D)), have been
  examined. Results of these comparisons
  indicate that ro.ughly half of the 95
  individual target compounds (from the
  11 wastes examined in both Phases I
  and II), were within —32 percent and
  + 76 percent of their respective field
  lysimeter target concentrations. Roughly
,  three-fourths of .the 95 individual target
  compounds were.within'---80 percent
  and +86 percent of their respective field
, lysimeter target concentrations (Ref. 25),
    The standard deviation of the total
  distribution (which is skewed) in this
  case is 182 percent. These preliminary
  numbers indicate that the acetate buffer
  system duplicates field lysimeter target
  concentrations  for approximately three-
  fourths of the target compounds within
  one standard deviation of the
  distribution. This is particularly
  significant since the laboratory test
  duration is 18 hours, whereas the field
  lysimeter experiments were run for
  approximately 3 months. EPA believes
  that the accuracy of the TCLP is
  adequate .in terms of indicating the
 potential for wastes to pose a hazard if
 mismanaged.
   b. Use of TCLP for sewage sludge
 disposal. EPA expects to propose in-
 September 1986 sewage sludge       '
 management standards under Section
 405(d) of the Clean Water Act. Once the
 Section 405(d) standards are
promulgated, EPA is considering
 exempting sewage sludge from RCRA
regulation. The section 405(d) standards
will tailor EPA's control strategy to the
management of specific risks to human
health and the environment from each of
the sludge use and disposal practices.
The Agency solicits comments on this
potential approach to regulating sewage
sludge.
•  C. Extent of experimentation. Another
issue  related to accuracy is whether
EPA has examined enough
contaminants and waste types in its
TCLP development program. The TCLP
was developed based on data from 11  ;
wastes and 95 target compounds which
leached from these-wastes (Ref. 6 and
7). The amount of work involved here is
substantial. EPA is aware, however, of
one waste type, specifically wastes of
moderate to high alkalinity, that was not
adequately represented by the 11
wastes, and has included provisions in
the TCLP to insure that the potential
environmental damage that may be
caused by such a waste was not
   underestimated. (These changes are '
   detailed further in this section).. '
     Additional testing aimed at evaluating
   the need to modify the TCLP extraction
   fluid to alter its solubilizing potential is
   not believed to be necessary. In addition
   to the work  described in section VIII (D),
   the Agency had earlier conducted two
   studies that evaluated the effect that
   changes in extraction fluid composition i;;
   would have  on solubilizatiori of organics'
   (Ref. 19 and 24). These studies examined
   the effect of adding acetic acid, •
   carbohydrates, protein, tannic acid, '     .
   citrate, thiosulfate, and a  surfactant Id
   the leaching medium. Both studies
   showed little" change in toxicant
   solubility and extraction efficiency with
   the addition of these various solubilizing
  agents. This  agrees well with the work
  done to develop the TCLP (Ref. 6 and 7),
  which also showed that leaching seems
  to be unaffected by, minor changes.to
  primarily aqueous extraction media.
  Thus, EPA believes that further testing
  is unlikely to result in a significant
  change in extraction fluid  composition.
    d Mismanagement scenario. RCRA  .
  requires EPA to identify those wastes
  which pose a potential hazard to human •
  health or the environment if
  mismanaged. In determining what form
  of mismanagement to model'in
  developing the  TCLP, the Agency
  considered several alternatives. These
  included segregated management, co-
  disposal with municipal refuse, co-
  disposal with industrial waste in a
  Subtitle D landfill, arid co-disposal with
  industrial waste in a Subtitle C.landfill
  which suffers some form of containment'
.  system failure.                      '
   For wastes which are not defined as
  hazardous (e.g., do not exhibit the .
  proposed toxicity characteristic), the
  Agency has concluded that disposal in a
  Subtitle C (hazardous waste) landfill is
  not a reasonable mismanagement
  option. In the  absence of regulation,
  there is no reason to expect that waste
 would go to the  more expensive Subtitle
 C facilities. The Agency believes that it
 is reasonable  to base its regulations on
 adverse effects when in a non-Subtitle C
 environment.
.   For the three remaining options,
 segregated management, co-disposal   •
 with municipal refuse, and co-disposal
 with industrial refuse in a Subtitle D
 landfill, the Agency believes that, in
genera.!, each is a plausible  -.
mismanagement scenario. Industrial
facilities dedicated to the management
of only one waste, or the waste from
only one generator, are likely to pose
less of a hazard than would general
sanitary or industrial landfills, since the
design and operation problems are

-------
                    Federal Register /Veil, 51, No, 114 /Friday, June 13,.1986 /PrpppsedRuIea
                                                                       21655
 simpler and the operator has much more
 information on the properties of the
 wastes before and while the facility is in
 operation. To insure that industrial  •  _
 wastes are adequately managed, EPA .
 has'proposed to employ the more -
 protective sanitary landfill scenario.
   The Agency believes that sanitary
 landfills may pose more of a potential
 hazard thaii industrial landfills. Many
 States have required some additional
 protection (e.g., more stringent siting
 requirements) at industrial landfills. The
 Agency, however, solicits comments on
 the choice of the sanitary landfill    ;
 scenario, and specifically requests any
 evidence that another disposal scenario
 may represent the worst-case plausible  .',•
 mismanagement.
   The scenario selected for .the TCLP, as
 well as for the current EP, was co-
 disposal with municipal waste in a
 sanitary, landfill. EPA selected this co-
 disposal scenario since Subtitle D
 sanitary landfills have traditionally
 accepted noft-hazardous industrial .   :
 wastes.'A recent survey conducted for  ..
 the Office of Solid Waste (Ref. 14)
 concluded that ". . ,. in general, Subtitle
 D landfills accept industrial wastes but
 not organic solvents or liquids/'.Wastes
 do have the potential to be subject to    .
 more aggressive conditions that might
 be better modeled through the use of
 strong inorganic acids, alkalies, or
 solvents.
    The survey noted above, however,
 found that Subtitle D facilities generally
 take only small amounts of organic
 solvent wastes (i.e., <1 to 2 percent of
 the total waste accepted). In addition,
 EPA will consider listing specific wastes
  as hazardous, when their normal
- management or their potential for
  mismanagement suggests more
  aggressive conditions. The Agency
  solicits comments on the fate of
  industrial wastes, the 5% industrial
  waste, 95% municipal waste assumption
  used in developing the leaching
  procedure, and the level of solvents
  which can be found at Subtitle D
  landfills.
    The Agency recognizes that not all
  industrial waste, or even wastes from all
  industries, go to Subtitle D sanitary
  landfills. The Agency believes, however,
  that this scenario is a reasonable worst-
  case and that some industrial wastes go
  to such facilities. In addition, it could be
  a serious administrative problem to
  define hazardous waste characteristics
  based on waste-specific or industry-
   specific disposal scenarios [including
   different leaching media) for the many
   different wastes generated. Even if .
   different toxicity characteristics could
   be created, difficult enforcement issues
   would result. For example, if the Agency
discovered an uncontrolled waste
situation (e.g., waste disposed in an
open pit) it might be difficult to
determine what characteristic test
should apply to the waste because there
may be very little available information
about how the waste was generated.
Moreover, even where some information
existed about the source of the waste,
the Agency believes that the existence
of varied toxicity tests would encourage
disputes about which test should apply
to a particular waste.
   It is therefore reasonable to use a
Subtitle D sanitary landfill as a general
model of how industrial wastes might be
disposed. The Agency, however, solicits ,
comments on whether this scenario is
appropriate for.all wastes. Commenters
identifying-a different scenario for
particular wastes  should explain why *
the Subtitle D sanitary landfill model is .
inappropriate and what disposal
 scenario would be appropriate for those
 wastes, including a discussion of what
 leaching medium is suggested by that
 scenario. In response to this    •
 information, ;the Agency may develop
 special management standards for a
. class or classes of wastes.       ,
•' As an additional matter, the Agency
 believes that the predicted degree of
 contaminant concentration in leachate
 could reasonably occur in the course of
 other types of land based waste
 management (e.g., surface
 impoundments). The TCLP, as well as
 the EP, basically involve mixing the
 waste  with an aqueous leaching media,
 and seeing if certain contaminants can
 migrate from the waste to a significant
 degree. If such mobility is demonstrated,
 EPA believes that the waste in question
 poses  a potential hazard to ground   '
 water, and that proper management
 controls need to be instituted to
 preclude unacceptable contamination of
 ground water. This applies to the
  leaching of both organics and          4
  inorganics.
    First, as discussed previously, minor
  changes to primarily aqueous media do
  not generally affect the leaching of
  organic compounds. For inorganics, the
  acidity afforded by the TCLP leaching
  fluid accounts for the possibility that
  wastes could be  subjected to mild acidic
  conditions-occurring in other types of
  land disposal environments.
    Wastes do have the potential to be
  subjected to more aggressive conditions
.  that might be better modeled through the
  use of strong inorganic acids,  alkalies, or
  solvents. The surv.ey referred to earlier
  (Ref. 14) found that Subtitle D facilities
  generally take only small amounts of
  organic solvent wastes (e.g., <1 to 2
  percent of the total waste accepted). In
  addition, EPA will consider listing
 specific wasteis as hazardous, when
 their normal management or their,      .;
 potential for mismanagement dictates   '
 more aggressive conditions.
   e. Treatment of highly alkaline
 wastes. As mentioned previously, highly   -
 alkaline wasteis were not adequately
 represented by the 11 wastes used.in the
 TCLP development program. EPAJs
 concerned that the potential hazard
 posed by these wastes may be
 underestimated by the acetate buffer   ;
 system initially chosen for the TCLP
 (See section VIII(D)). Specifically, EPA -,
 believes that an increase in the leaching
 of inorganic aind some organic species
 may be  observed as the alkalinity of
 wastes becom.es exhausted due to
 continuous contact with an acidic
 leaching medium. Note that this can
 occur well after the 20 to 1 liquid to solid'
 ratio selected;for the EP and TCLP. Data
 from the TCLP development program (on
 a moderately alkaline waste), arid from
 subsequent studies on wastes, of ....
 moderate to high alkalinity (Ref. 8),
 demonstrated that the leaching rate of ,.
 heavy metals [was relatively constant;.
 and in some cases increased slightly,
 over.liquid to-solid ratios;as high as 30
 to 1. Constituents from non-alkaline.
 wastes generally experience a decrease
 in leaching rate  during this time period
 (Ref. 6 and 7). The TCLP acetate buffer
 leaching fluid may therefore not
 adequately account for the leaching of
 " heavy metals; from wastes of moderate
 to high alkalinity.
    To address this problem, EPA
 determined that an increase in the
 acidity of the leaching medium for the,
 alkaline wastes would adequately
 account for the increased leaching of
 these species, that could eventually
  occur in landfills..To define this second
 leaching fluid, the basis behind the EP's
i! maximum amount of acetic acid (i.e., 2
* milliequivalents of acid per gram of
 .'. waste) was used in defining a second
  leaching fluid to be used when
  evaluating highly alkaline wastes. Data
  gathered at EPA's Boone County Field
  Site over a period of 7 years indicated
  that the leachate generated by
  decomposing municipal waste contains
  approximately 0.14 equivalents of
  acidity per kilogram of dry refuse.
  Applying this data to the hypothetical
  co-disposal environment, EPA
  concluded that 1 gram of industrial
 . waste could potentially be acted upon
  by 2 milliequivalents of acid. For a
  hundred gram sample (the EP's minimum
   sample size), this translated to a total of
   200 milliequiivalents of acid (Ref. 26).
   The acetate buffer systeni'originally'
   chosen for th,e TCLP supplies only 70

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l£feral Register / Vo1- 51» No-114 / Friday, June 13, 1986 / Proposed Rules
  milliequivalents of acid for a hundred
  gram sample.
    As indicated above, steady or
  increased leaching of inorganic species
  was demonstrated to occur up to and
  after the 20 to 1 liquid to solid ratio (Ref.
  8). While this data demonstrates that the
  70 milliequivalent acetate buffer system
  is not aggressive enough for most of the
  inorganic species investigated, it
  supports the use of a 200 milliequivalent
  acetic acid solution for only some of the
  inorganic species. The Agency is,
  however, proposing use of the 200
  milliequivalent acetic acid solution for
  alkaline wastes to be protective of
  human health and the environment
  when such leaching does occur. The
  Agency believes this action is justified
  given the conservative nature of the'
  Hazardous and Solid Waste
 Amendments of 1984. In addition, as
  indicated in the report on Phase I of the
 TCLP development effort (Ref. 6),
 municipal waste leachates, both those
 generated in lysimeters and real
 leachates, have been observed in other
 studies to contain higher concentrations
 of carboxylic acids [measured as total
 organic carbon, of which approximately
 70 percent is made up of carboxylic
 acids  (Ref. 6)), than those measured in
 the municipal waste leachate used in the
 TCLP development program.
   Hence, EPA is proposing a two
 leaching fluid system for the TCLP. As
 explained above, the Agency has chosen
 to base the strength of the alkaline
 waste leaching medium on the basis
 behind the EP's limit on the amount of
 acetic acid used. This will involve a 2
 milliequivalent of acid per gram of
 waste leaching fluid for wastes of
 moderate to high alkalinity and a 0.7
 milliequivalent per gram of waste
 leaching fluid for other wastes. A simple
 tost of waste alkalinity is proposed as a
 means of  determining the appropriate
 leaching fluid. For highly alkaline
 wastes (i.e., alkalinity> 0.7
 milliequivalents/gm), the more acidic
 leaching fluid would be used. Note that
 EPA is not proposing this dual leaching
 fluid system for the evaluation of
 volatile compounds, since these
 compounds are expected to be
 unaffected by slight changes in acidity.
 More detail is provided in Section VIII
 (D) and in the background document
 supporting the TCLP (Ref. 33).
  / Use of a pre-screen test. One
 concern that was raised with the TCLP
xvas that the protocol for dealing with
volatile compounds is likely to be
considerably more expensive than the
protocol for  the non-volatiles. Similarly,
since this proposal involves additional
analytes, the analytical costs associated
                   • with the TCLP protocol will also
                    increase over that of the EP. For these
                    reasons, EPA is proposing to establish a
                    pre-screen test for the TCLP protocol.
                    This pre-screen consists of a total
                    analysis of the waste itself (using SW-
                    846 methods, Ref. 27)), to determine if
                    the waste contains sufficient amounts of
                    "specific compounds for the regulatory
                    level to be exceeded, assuming that all
                    the compound leaches from the waste. If
                    based on such an analysis one can be
                    certain that the regulatory level  cannot
                    be exceeded, then the TCLP does not
                    have to be performed.
                      This pre-screen is being  offered as a
                    cost saving alternative, and is not
                    mandatory. It will be especially useful to
                   , those generators who wish to
                    demonstrate that their waste does not
                    contain sufficient amounts of certain
                    compounds, and therefore, that further
                    analysis would be unnecessary. Perhaps
                    a prime  example of this is wastes
                    resulting from a combustion process,
                    like ashes  from incineration. Since these
                    wastes would likely be devoid of
                    volatile components running the TCLP
                    for volatiles would be unnecessary.
                    2. Technical Issues

                     a. Use of extraction devices. The EP
                    protocol contains a descriptive
                    definition of what was considered to be
                   acceptable agitation. Two types of
                    extraction  equipment are described
                   which EPA has determined meet this
                   definition.  One is a stirrer type extractor
                   which uses small fan-like blades to mix
                   the extraction fluid with the waste. The
                   other type involves rotary action in
                   which closed bottles containing the
                   waste/extraction fluid mixture are'
                   tumbled in an end over end fashion (Ref.
                   27). This lack of specificity in agitation
                   conditions  is a major source of
                   variability.
                  £• Today's proposal eliminates this
                   source of variability by specifying a,
                   single means of agitation (i.e., rotary
                   tumbler), and a fixed agitation rate
                   (30±2 rpm). The rotary of tumbler type
                   of extractor was selected for several
                   reasons. It is widely recognized as a
                   reproducible means of contacting the
                   liquid and solid, and has been
                   standardized by ASTM in their draft   .
                   method D3987 (Ref. 1). Also, ,a factor in
                   this determination was that the
                   Agency's Science  Advisory Board
                   (SAB), in reviewing the TCLP
                   development program, recommended
                   that EPA develop  one device and one
                   set of operating conditions (Ref. 29).
                   Although EPA recognized that this
                   would require laboratories to purchase
                   additional equipment, EPA has opted to
                   propose the use of rotary agitation only.
    Another related issue deals with the'
  extractor vessel. As discussed in section
  VIII (D), EPA has developed a zero-
  headspace extraction vessel (ZHE) for
  use when extracting wastes with
  volatile organic compounds. This device
  can accommodate liquid/solid
  separation within the device, and
  obviates the need for an outside
  pressure filtration apparatus.'One issuer
  associated with use of this device is
  that, due to its 500 ml internal capacity,.
  it can only accommodate a maximum
  sample size of 25 grams for a 100 percent
  solids sample. (A device of the normal 2
  liter capacity was impractical due to its
  large size and weight.) For a waste of
  less than 100 percent solids, the
  maximum sample size the device can
  accommodate is tied to the percent -
  solids of the waste. The device can only
  accommodate the minimal 100 gram
  sample size for wastes that are 25
  percent solids or less.
   Another problem associated with the
  extractor is  that while EPA is proposing
  to require the zero-headspace extractor
  when dealing with volatiles, EPA is
  requiring use of regular extraction
  bottles when dealing with metals and
  other-non-volatile components. Regular
  extraction bottles are much less
  expensive and easier to use than the
  zero-headspace vessel. The problem is
 "that while EPA originally intended the
 zero-headspace extractor to be allowed
 to be used for metals and non-volatiles
 as well, certain features of the device,
 and other constraints, have led EPA to
 allow its use only when dealing with
 volatiles.
   The problem touches upon the SAB's
 concern that, in the interest of precision,
 one device and one set of operating
 conditions should be specified (See
 section VIII(D)). There are actually two
 factors here which differ between
 regular extraction bottles and the zero-
 headspace vessel which could affect
 precision. The first is that since regular  _
 extraction bottles will provide for at
 'east some-headspace, agitation is likely
 to be slightly greater than' with the zero-
 headspace vessel.
  «The second factor is that the two
 devices involve different types of liquid/
 solid.separation techniques. Whereas
 the ZHE requires piston-applied
 pressure, use of bottles involves
 conventional air pressure filtration.
 These two means of applying pressure
 to accomplish liquid/solid separation
.are capable of producing different
 results for some waste types.
  b. Particle size reduction. The EP
 protocol requires particle size reduction
 in those cases where the waste cannot'
 pass through a 9.5 mm sieve, or has a

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                     Federal Register/'Vol. 51. No-114
                                                                                                                21657
 surface area of less than 3.1 cm2/gm.
 The TCLP continues with this
 requirement. One difference, however,
 deals with particle size reduction for
 monolithic type wastes. The EP allows
 the alternative of using the Structural.
 Integrity Procedure (SIP), which
 amounts to p'ounding the monolithic
 waste with hammer-like blows and then
 conducting the extraction on the
 resulting sample, whether in one piece
 or in many pieces. The proposed TCLP
 does not allow use of the SIP (i.e.,
 requires particle size reduction) for
 several reasons. The first reason again
 has  to do with precision and the Science
 Advisory Board's comment to limit the
 new procedure to one device and set of
 operating conditions. Secondly, the
 Agency believes that given the '
 uncertainties concerning the long term
 • environmental stability of solidified
 wastes, an environmentally     "
  conservative approach is warranted.
 The SIP was originally developed as a
  means of assessing the degree to which
  a cementitiqus process stabilized a
  waste to  the extent that the waste
  would remain as a monolithic block
•  even after disposal. Such stabilization
  processes decrease leaching potential
  through reduction of surface area, and
  thus the area of potential leachate
  contact. Many processes also provide
  for  chemical stabilization by binding
  heavy metals in insoluble hydroxide and
  other complexes.    ,
    The Agency_believes that physical
  stabilization alone is not enough to
  insure that components do not leach in
  significant quantities from wastes. There
  are two types of actions which may act
  to reduce the, physical integrity of
  stabilized wastes. First, the action of  •
  heavy landfill equipment,  which the SIP
  is designed to simulate, will act to
  reduce, the monolithic blocks  into
  smaller pieces. Secondly,  and more
  important, is the effect of natural
  weathering forces, such as wet/dry and
  freeze/thaw cycles (Ref. 10). The SIP
   does not account for such weathering.
  The Agency is currently investigating
   the effects of natural  weathering on
   monolithic wastes, and may propose the
   use of additional predictive  ,    .   ;
   methodology at some later date. In the
   interim, by not allowing use of the SIP,
   the Agency insures that generators do,
   not rely on physical stabilization alone.
     An unrelated issue regarding particle
   size reduction also involves the
   treatment of volatile  compounds. While
   EPA is attempting to prevent loss of
   volatiles (through introduction of the
   ZHE), if a waste containing volatiles
   requires particle size reduction, it is
   likely that some portion of these
volatiles will be lost before the waste is
introduced into the ZHE.
  Herein lies a problem that may
require a trade-off. Is it more important
to 'reduce particle size or to prevent the
loss of volatiles? EPA believes that
particle size reduction is more important
and has addressed this problem in the    .
draft TCLP protocol by specifying that,
where possible, particle size reduction
be conducted to the extent possible on
the sample as it is being taken.
  The protocol does recognize, however,
that there will be situations where_
volatile containing samples requiring
particle size reduction cannot be  '
reduced under these conditions. In'this
: case, the protocol specifies that the
sample should first be refrigerated to
reduce the vapor pressure of the
volatiles, and then that the particle size
should be reduced with minimal
.exposure to the atmosphere to, at least, .
minimize the loss of volatiles. Another
 alternative is to require* extractions r
 under both conditions. Comments and
 alternative suggestions regarding this
 issue are solicited.                     .
   c. Quality assurance requirements.
 The quality assurance requirements of
 the EP are relatively straightforward.
 They require a minimum of one blanket
 per sample batch, and the method of
 standard addition (MSA) to be run for
 all samples. The Agency has received
 comments that requiring MSA for all
 extractions, which is very expensive, is
 unnecessary for all situations. This issue
 is particularly significant in determining
 the quality assurance requirements for
 the TCLP, given  the increased number of
 analytes. In addition, the EP protocol is '
 felt to need clarification and expansion
 in addressing other aspects of quality
 assurance, such as sample holding
 times.
    The reader is referred to section 9  of
  the draft TCLP protocol, which appears
  as Appendix irto.Part 261 in the
  regulation section of this proposed rule
  for review of the quality assurance
  requirements. One change that deserves
 'mention here is in the requirement for
  the method of standard addition (MSA),
  Recognizing that MSA is expensive and
  not always necessary, EPA is proposing
  to require MSA only under certain
  conditions (See Proposed Appendix  II to
  Part 261). This change recognizes that
  MSA is necessary only when the
  measured concentration; of a constituent
  is close enough to the threshold, that
  matrix .interferences could yield a wrong
  decision regarding the determination of
  hazard, or when there is evidence that
  severe matrix interference' may be
  present.                  -
IV. Other Aspects of Proposal

A. Testing Frequency and ..  \
Recordkeepirig           '.
  Under the framework being proposed
today, the determination of whether a
waste is a hazardous waste depends on
whether the concentrations of
constituents in the TCLP extract exceed
the applicable'regulatory levels. Since
this determination is critical, EPA is
evaluating whether to require periodic
waste testing;
.  EPA has identified three general
approaches to testing requirements,
which are discussed in detail below.
First; EPA could require generators to.
 evaluate their wastes as to whether they
 exceed applicable regula.to.ry levels, but
 not specifically require testing to make
 this determination. This approach is
 consistent with the current application
 of the RCRA hazardous waste
 characteristics. Second, .EPA could
 require testing of wastes at a frequency
 specified by regulation. Third, EPA
 could require! the generator to test,
 documenting the determination" of the
 appropriate testing frequency based on
 guidance provided by the Agency.
   As indicated above, existing
 regulations (40 CFR 262.11) require
 generators of solid wastes to determine
 whether their waste is hazardous. If the
 solid waste is not specifically excluded
 from regulation, and it is hot listed as a
 hazardous waste in Subpart D of 40 CFR
 Part 261, then,the generator must
 determine whether the waste is
 hazardous by any of the hazardous
 waste characteristics included in
 Subpart C p'F 40 CFR Part 261. This .
 determination may be made by either
 testing the waste or by the application
  of knowledge of the waste in light of the
 materials or the processes used in its
  generation. Under 40 CFR 262.40,
 , generators eire required to keep records
  on how the hazard determination was
•• .made. Thus,' although generators are
  held responsible for determining
  whether their-wastes are hazardous,
  they are noli specifically required to
  perform testing. :
 -" Although this approach would place
  the least burden on the regulated
  community,; EPA is concerned that this
  approach may not promote voluntary
  compliance; and that it could hamper
  Agency enforcement efforts against
  those members of the regulated   • .  „  •
  community that do not comply  -
  voluntarily-with the regulations.
     Another possible approach is to
  require periodic testing, specifying in the
  regulations'both the method arid the
  frequency of testing. Thusj.testing might
  be required, on a semiannual, or annual

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Federal Register / Vol. 51,. No. 114 / Friday, June 13, 1986 / Proposed Rules
  basis. This approach would make
  enforcement of the regulations easier
  and would likely induce a higher level of
  voluntary compliance since the
  regulations would be highly specific
  regarding what constitutes an
  acceptable testing program and what
  actions and inactions would constitute
  violations.
    There are, however, several problems
  with such an approach. First,  there are
  problems inherent in specifying an
  appropriate testing frequency. Based on
  data from the Office of Solid Waste's
  Industry Studies Program and data from
  the Office of Water's Effluent Guidelines
  Program, it is clear that many waste
  streams are extremely variable in
  concentrations, of chemical constituents
  from one plant to another, even when
  the same general process is employed.
  Variability exists not only from one ,
  generator to another, but also spatially
  and temporarily within a single plant or
  process. This variability can be caused
  by plant start-ups and shut-downs,
  changes in raw materials, changes in
  product specifications, seasonal
  changes, or meteorological events.
 While these factors tend to indicate the
 desirability of requiring testing at
 frequent specified intervals, the process-
 specific nature of this variability [among
 others) makes it difficult to identify a
 generically appropriate testing interval.
 For example, an appropriate frequency
 for a continuous process might be too
 infrequent for a batch process.
   The third possible approach is to
 require generators to perform testing on
 their wastes, but not to specify a testing
 frequency in the regulations. Rather,
 generators would be required to
 determine an appropriate testing
 frequency based on guidance developed
 by the Agency and to  document, in their
 records, this frequency determination.
 The advantage of this approach is that
 process-specific factors could be taken
 into account in determining the
 appropriate testing interval. Thus,.
 although there would be some
 additional burden on generators to
 determine, based on the guidance, the  -
 appropriate frequency for testing
 tailored to specific factors relating to his
 process, there would be less of a chance
 of requiring unnecessarily frequent
 testing. This approach does, however,
 present greater enforcement difficulties
 than does the approach of specifying
generic periodic testing intervals.
  Even if testing is specifically required,
a problem still remains as to how to
assure that the waste sample subjected
 to testing is representative of both the
batch and the process  from which they
are derived. This problem arises not
                    only in the context of the Toxicity ,
                    Characteristic program, but also in
                    connection with other waste sampling
                    requirements. EPA is currently
                    developing a guidance manual on
                    representative sampling that will
                    address these concerns and anticipates
                    publishing that guidance in late 1986.
                     EPA is proposing to retain "the
                    requirement that generators evaluate
                    their wastes as to whether they exceed
                    applicable regulatory thresholds, but not
                    specifically to require periodic testing.
                    EPA is, however, requesting comments
                    on the approaches discussed above,  as
                    well as other possible alternatives to
                    these  approaches.
                   B. Relationship To Multiple EP and Oily
                    Waste EP
                     As a result of its waste listing
                   program, EPA has listed a number of
                   wastes as being hazardous on the basis
                    that these wastes typically or frequently
                   contain hazardous constituents at
                   significant levels, or that they typically
                   or frequently exhibit one or more of the
                   characteristics of hazardous wastes.  In
                   recognition, however, that individual'
                   wastes may not actually be hazardous,
                   due perhaps to a different process or'the
                   use of different raw materials, EPA has
                   established a  "delisting program,"
                   where generators could demonstrate  to
                   EPA that the particular waste in
                   question does not constitute a
                   hazardous waste. Although no waste to
                   date has been listed because it exhibits
                   the EPTC, -the delisting program has
                   been applying the EP protocol to this.
                   determination for the metal
                   contaminants  (with the application of a
                   more conservative dilution/attenuation
                   factor).
                    Given that the delisting process
                   involves a more waste specific
                   approach, a number of situations have
                   arisen  which have led EPA to modify  the
                   EP to address specific situations. The
                   use of multiple extractions with
                   simulated acid rain have been used to
                   predict any long-term effects acid rain
                   might have on stabilized wastes (the
                   Multiple Extraction Procedure or MEP),
                   and the Oily Waste EP (OWEP) has
                   been used to predict the leaching of.
                  metals from wastes which contain
                   significant amounts of oily materials.
                  The OWEP was adopted because of the
                  Agency's concern that the oil present  in
                  the wastes  may (1) degrade, thus
                  permitting the metals to be leached from,
                  the residue, or (2) migrate,itself, and
                  transport metals present in the organic
                  phase to the ground water.
                    The Agency has a number of studies
                  underway to better define the situations
                  when such modifications are required.
                  Pending completion of such studies the
  Agency will continue to employ the MEP
  and OWEP only in the listing and
  delisting programs where situation
  specific decisions caii be made.

  C. Analytical Methods

   The analytical methods proposed to
  be used for TCLP extracts are shown in
  section VIII(C) (See Table C-2), and also
  appear in the regulation section of this
  proposal as required methods. These are
  SW-846 methods (Ref. 27).
   Analyzing the TCLP extract for
  phenolic compounds and phenoxy acid
  herbicides poses a potential analytical
  problem. The leaching fluid used in the
  new leaching procedure is 0.1 M with
  respect to acetate. Due to potential
  interference from the acetate ion, the
  routinely used analytical methods used
  for these compounds (i.e., GC/MS-SW-
  846 method 8270) may not be sufficient.
  EPA is presently investigating these
  methods to ascertain whether they are
  sufficient, or, whether it may be
  necessary to modify these methods. One
  modification being investigated is
  whether it may be possible to remove
  the acetate ion from the extract before
  determination of the phenolics and
  herbicides.
   EPA is also investigating the use of
 high pressure liquid chromatography
  (HPLC) using .electrochemical and
 fluorescence detection. HPLC with
 fluorescence detection was used in
 developing the improved leaching
 procedure, and has been shown to
 produce acceptable results (Ref. 6 and
 7). A GC/MS method would be
 preferable since use of the HPLC
 method could add significantly to
 analytical costs. Should the presence of
 the acetate ion present substantial
 problems to GC/MS, it is likely that   ,
 HPLC may be specified.
   These methods are currently being
 evaluated. The Agency solicits
 comments arid data on these or other
 methods which may be appropriate. On
 completion of these studies and
 evaluation of data received, a method
 for the phenolics will be selected and
 proposed for use with, TCLP extracts
 prior to promulgation of this rule.

 D. Notification Requirements

  The Agency has decided not to
 require persons who generate, transport,
 treat, store, or dispose of these
 hazardous waste to notify the Agency
 within 90 days of promulgation that they
 are managing these wastes. The Agency
views the notification requirement to be
unnecessary in this case since we
believe that most, if not all, persons who
manage these wastes have already
notified EPA and received an EPA

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Federal Register /Vol. 51. No. 114
                                                                                  ^opose(*
                                                                                           21659
 identification number. In the event that
 any person who generates, transports,
 treats, stores, or'disposes of these
 wastes has not previously notified and
 received an identification number, that
 person must get ah identification
 number pursuant to 40 CFR 262.12
 before he can generate, transport, treat,
 store, or dispose of these wastes.
 V. Relationship to Other Regulatory
 Authorities                           :
   As has been pointed out previously,
 the Toxicity Characteristic threshold
 setting approach is modeled along the
 same lines as that used in the January
 14,1986 proposed standards for
 implementing the Land Disposal  ,
 Restrictions regulations (51 FR1603).
 However, since the Toxicity
 Characteristic proposes to use a Subtitle
 D disposal model, a slightly broader
 confidence interval for the Monte Carlo
 simulation, and an order'of magnitude
 higher risk level for the carcinogens, the  ;
 regulatory thresholds may be different
  than those proposed for banning wastes
  from land disposal.      '
    The reason for the different thresholds
  in the Toxicity Characteristic relates to
  the nature of characteristics and the
  relationship between characteristics and
  listings, as discussed previously in this
. .preamble. Characteristics are designed
  to be self implementing hazardous
  waste definitions in which waste and
- • management specific factors are not
 • considered. For that reason,
  characteristics are established.at levels
  at which the Agency has a very high
  level of certainty that a waste which
  exhibits these properties, needs, to be
  managed in a controlled manner (i.e., is
„  a hazardous waste). The Agency
  realizes that not all waste which exhibit
 .-' properties at levels below the
  characteristic are safe for disposal as
  nonhazardous waste. Rather, for those
 ' wastes having properties lower than the
 . characteristic levels, and which are
  demonstrated to pose a hazard to
  human health or the environment, the
  Agency undertakes waste specific
 . evaluations under the auspices of its
  listing program. Wastes which are
   determined to require controlled
   management after consideration of the
   factors identified in 40 CFR 261.11(a}(3),
   (e.g., the nature of the toxic constituents,
   toxicant mobility under various
•  environmental management scenarios,
   volume of waste generated, potential
   methods of management), are then
   specifically listed as hazardous wastes
   and subjected .to the appropriate RCRA
   management controls.
     For the land disposal restrictions
   program, the screening levels, identified
                    through the equation are levels which,
                    EPA is very certain are protective at
                    Subtitle C land disposal facilities.
                    Wastes not meeting the screening levels
                    are not banned outright from land-
                    disposal, but rather subject to qase-by-
                    case evaluations taking into account the
                    specific characteristics of individual
                    facilities. This case-by-case
                    determination is initiated by petitions.
                    for exmption from the land disposal
                    restrictions. The evlauation of these
                    petitions will be based on results of
                    modeling similar to that used to set
                    screening levels, but with site-specific
                    rather than conservative generic factors
                    included.                     ,
                      In addiiton, the HSWA requires a very
                    ' high standard of proof for a showing
                    that a hazardous waste is suitable for
                    land disposal. For this reason, the
                    Agency believes it is appropriate to use
                    a higher level of confidence and a lower
                    cancer risk level in the modeling for the
                    land disposal restrictions decisions,
                    than is used for the Toxicity
                    Characteristic. However, the Agency
                    requests comment on whether the risk
                    level and confidence level used in the
                    Toxicity Characteristic should be the
                    " same as for. the screening levels used in
                    the proposed land disposal restrictions
                    rule.                 -,',-.
                       Whenever a waste or waste stream is
                    determined to be hazardous under
                     section 3001  of RCRA, it automatically
                     becomes a hazardous substance under
                     section 101(14) of the Comprehensive
                     Environmental Response,
                     Compensation, and Liability Act of 1980
                     (CERCLA). CERCLA section 103
                     requires that persons in charge of
                     vessels  or facilities from which
                     hazardous substances have been
                     released in quantities, that are equal to
                     or greater than the reportable quantities
                     (RQs), immediately .notify the National
                     Response Center (at (800) 424-8802 or
                     (202) 426-2675) of the release. (See 50 FR
                     13456, April 4,1985).   '
                       The term "hazardous substance"  .
                      includes all  substances designated in
                      § 302.4(a) of the April 4,1985 final rule
                      (50 FR 13474), as well as unlisted    ., - • -
                      hazardous wastes exhibiting the
                      characteristics of Ignitability,^
                      Corrosivity, Reactivity, and Extraction
                      Procedure Toxicity (ICRE). (See
                      § 302.4(b) of the April 4..1985 final rule).
                        There are currently only 14
                      substances listed under CERCLA as
                      ICRE wastes oh the basis of the EP
                      Toxicity Characteristic, most of which
                      are  also specifically designated as
                      hazardous substances under 40 CFR
                      302.4(a). Under today's proposed rule, an
                      additional 38 compounds, which are also
specifically designated .as hazardous
substances under 40 CFR 302.4(a), would
be incorporated under the newly defined
Toxicity Characteristic. Accordingly,  ,
EPA proposes in this rulemaking to
amend Table. 302.4 of 40 CFR 302.4, to
remove "Characteristic of EP Toxicity"
and replace  it with "Toxicity
Characteristic," and to list the
additional Toxicity Characteristic
contaminants along with their final RQs
from Table 302.4.
  The CERCLA program will also use
the TCLP procedure to help determine
when waste( taken off-site must be  . ,
managed as a hazardous waste. To the
extent that the TCLP is applicable or
relevant and appropriate, the CERCLA
program will apply the TCLP in a
manner that is consistent with the
National Contingency Plan (NCP) (50 FR
47912, November 20,1985) and policy on
CERCLA compliance (50 FR 47946,
November 20,1985) with other
 environmental statutes.
   As indicated earlier in this preamble,
 under section 405 of the Clean Water
 Act (CWA), EPA establishes guidelines
 for the disposal and use of sewage
 sludge. The regulation of sewage sludge
" is necessarily a complex matter because
 these sludges fall within the jurisdiction
 of several Federal environmental
 programs. Under section 1004(27) of
 RCRA, the  definition of "solid waste"
 specifically includes "sludge from a
 waste  treatment plant." In defining
 "sludge," SBCtion 1004(26A) includes,
 wastes froih a "municipal wastewater
 treatment plant.". Under.section 102 of"
 the Marine Protection, Research and
 Sanctuaries Act, EPA regulates the
; ocean dumping of sludge, including,
 sewage sludge.
    Where silch overlapping jurisdiction
 exists, EPA seeks to integrate and  .
 coordinate its regulatory actions to the
 extent feasible. Thus, consistent with
 section 1006 of RCRA,  the Agency's
 strategy for the development of a
 comprehensive sewage sludge
 management regulation will result in the
  establishment of a separate regulation.
  Once  this regulation is in place, all
  sewage sludge use and disposal
  practices will be covered under
  appropriate provisions of section 405 of
  the CWA. If appropriate, sewage sludge
  that would be defined as a hazardous
  waste will be exempted from coverage
  under proirisions of Subtitle C of RCRA,
  once this separate, sewage, sludge
  regulation, which will provide an
  equivalent level of protection, is issued.

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  21660
Federal Register /Vol. 51. No. 114 /Friday, June 13,1986 /Proposed Ruies
  VI. Slate Authority
  A. Applicability of Rules 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, EPA retains
  enforcement authority under sections
  3008, 7003 and 3013 of RCRA, although
  authorized States have primary
  enforcement responsibility.       - '  .
    Prior to the 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
  Slate 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 lime frames. New Federal
 requirements did not  take effect in an
 authorized State until the  State adopted
 the requirements as State law.
   In contrast, under newly enacted
 section 3006(g) of RCRA, 42 U.S.C.
 G92C(g). new requirements and
 prohibitions imposed  by the HSWA take
 effect in authorized States at the same
 time that they take effect in
 nonaulhorized Stales. 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
 USWA-related provisions as State law
 to retain final authorization, the HSWA
 applies in authorized States in the
 interim.
  Today's rule would  be promulgated
 pursuant to sections 3001 (g) and (h) of
 RCRA. provisions added by HSWA.
 Thus, it would be added to Table 1 in
 section 271.1(j) which  identifies the
 Federal program requirements that are
 promulgated pursuant to HSWA and
 that take effect in all States, regardless
 of their authorization status. States may
 apply for either interim or  final
 authorization for Ihe HSWA provisions
 identified in Table 1, as'discussed in the
 following section of this preamble;
B. Effect on State Authorizations
  As noted above, EPA will implement
 today's proposed rule, when
promulgated, in authorized States until
.they modify their programs to adtfbt
these rules and the modification is
approved by EPA. Since the rule will be
                    promulgated pursuant to HSWA, a State
                    submitting a program»modification may
                    apply to receive either interim or final
                    authorization under section 3006(g)(2) or
                    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 under section
                    3006(b) are described in. 40 CFR 271.21.
                    The same procedures should be
                    followed for section 3006(g)(2).
                     Applying § 271.21(e)(2), States that
                    have final authorization must modify
                    their programs within a year of
                    promulgation of EPA's regulations if
                    only regulatory changes are necessary,
                    or within two years of promulgation if
                    statutory changes are necessary. These.
                    deadlines can be extended in
                    exceptional cases (40 CFR 271.21(e)(3]).
                     States with authorized RCRA
                    programs may already have
                    requirements similar to those in  today's
                    proposed 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 approved.
                   States with existing rules 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.
                    States that submit official applications
                   for final authorization less than ,12
                   months after promulgation of EPA's
                   regulations may be approved without
                   including standards equivalent to those
                   promulgated. Once authorized, however,
                   .a State must modify its program to
                   include standards substantially
                   equivalent or equivalent to  EPA's within
                   the time periods discussed above.
                   VII. Economic and Regulatory Impacts

                   A. Regulatory Impact Analysis
                   1. Executive Order 12291
                    Executive Order 12291 requires
                   regulatory agencies to conduct a
                   Regulatory Impact Analysis (RIA) for
                   any major rule. A major rule is one
                   likely to result in (1) an annual effect on
                   the economy of $100 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 in domestic or export markets.
    EPA conducted an RIA to compare
  several regulatory alternatives, as
  explained in the following sections. The
  RIA provides an analysis based on the
  guidelines contained in the Office of
  Management and Budget's "Interim
  Regulatory Impact Analysis Guidance"
  (Ref. 21) and EPA's "Guidelines for
  Performing Regulatory Impact
  Analyses" (Ref. 28).
    Based on the results of this analysis
  the Agency has concluded that this
  proposed regulation is a major rule with
  an annual cost to the economy of $151  •
  million and an annual benefit of $1,625
•million. The benefits, however, may be
  an overestimate since it is assumed that
  all contaminated aquifers would be
  cleaned up.-Thus, the savings attributed
  to not having to clean up those aquifers
  would not accrue with a resultant
  decrease in benefits. Due to the case-by-
  case nature of these cleanup decisions,
 , it was  not possible to quantify this
  qverestimatioh.
   The purpose of section VII(Al) is to
  summarize the methodologies and
  findings of the RIA. Section VII(A)(2)
  discusses the basic approach taken in  '
  the RIA, and provides the regulatory
  alternatives examined. Section VII(A){3)
  lists the industries projected to be
  affected by the proposed actions; and
  section VII(A)(4) discusses the
  methodologies employed in the
  economic impacts, benefit, and cost
 analyses. Finally, section VII(A)(5)
 reviews and compares the results of the
 benefit and cost estimations. The full
 draft RIA is available as part of one of
 the background documents supporting
 this proposed regulation (Ref. 22).
   This proposed rule was submitted to
 the Office of Management and Budget
 for review, as required by Executive
 Order 12291.          :

 2. Basic Approach/Regulatory
 Alternatives              '

  EPA is proposing to expand its list of
 contaminants under the EP Toxicity
 Characteristic to include a total of 52
 contaminants. As explained earlier, and
 in sections VIII (A), (B) and (C),
 regulatory levels for these contaminants
 have been established by multiplying
 the chronic toxicity reference level for
 the contaminant, by its compound
 specific dilution/attenuation factor.
 Since EPA was in the process of refining
 both its chronic toxicity reference levels
 for some of the compounds, and its
 ground water transport model, many of
 the actual levels proposed today could
 not be used in estimating regulatory
 impact.  Since the ground water
 transport model was in the process of  -
 being refined, straight dilution/

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                    Federal Register /Vol. 51, No. 114 /Friday, June 13,1986 /Proposed
                                                                        21661
attenuation factors of 10, WO, and 1,000
were applied to .estimated chronic   .
tpxicity reference levels",, to .arrive at "...,
three levels of regulation. Thus,
including the status quo [i.e., no
regulation), a total of four regulatpry. -'
alternatives were e'xamined.  .  ':..'; -  :
  This approach .was taken as it would
provide minimum and maximum .  • ,  .•  "
estimates pf regulatory impact, and also
because it provided EPA with
comparative cost and benefit is estimates
for three levels of-regulation. Since the
regulatpry levels for the elemental
drinking water standards are being
retained, and since the TCLP is expected
to be roughly, equivalent to the EP, this
RIA also assumes that the universe of
waste regulated as a result of the
elemental drinking water standards is ,
unchanged. Benefits and'costs were
determined, then, for the following  -    .
regulatpry alternatives:                 ,
  ' Alternative 1. Includes all currently
 unregulated wastes which would
 produce a TCLP extract containing any
 of the contaminants at a level greater
 than or  equal" to 100 times the chronic
 toxicity reference level.       '•'     '
   Alternative 2. Same as above except
 this alternative evaluates, a level greater
' -than or equal to, 10 times the chronic  .',
 toxicity reference'level.      '       ;
   Alternative 3. Same as above except
 this alternative evaluates a level greater
 than or equal to 1,000 times the chronic
 toxicity reference level.
   Alternative 4. Status quo (i.e., no
 regulation).
   The proposed regulation, since it
 employs compound specific attenuation
  factors, does not exactly mirror any of
  the alternatives studied. Rather, it falls
 between alternatives 2 and 3, with 40  . ;
  compounds having a dilution/
  attenuation factor of 14.4, and 12  "'-.':
  compounds with factors ranging from 18
  to 150 (See section YIII(C). As will be
  seen from the discussion which follows,
 'alternatives 1 and 2 both yield almost
  identical results for both costs and
  benefits. Thus,, basing the conclusions
  on the results of alternatives 1 or 2 are
  not expected to result in any significant
  difference.
    Benefits and costs for each regulatory
  alternative are compared to those of the
  baseline status quo. The status quo is
  assumed not to require industry to incur
  additional waste management costs.
  However, this RIA assumes that society
  will incur, the costs of not regulating  :
  these wastes. The. "social" costs of the
  status  quo are.assumed:to be the.;.
  benefits .that would occur if the wastes
  were regulated. They vary with .the  . ,
  projected number of affected facilities.
    .Note that no original research,   '  •
  sampling, or analyses were conducted
as.part of this RIA. In addition, as in alf
RIAs, a number pf assumptions were
made in order, to predict impacts  .
Assumptions about potentially affected
wastes were based primarily on.
technical judgment, review of available
literature and data, and EPA guidance.
The determination of whether wastes
would be hazardous under this proposed
rule was based primarily on the
solubility of individual contaminants"
rather than actual testing or data.
Consequently,  EPA believes that the
estimates of projected impact indicated
in the following paragraphs, are_
conservative (i.e., overstated) and
should be viewed in a relative'sense. In
 addition, although EPA expects to have
better impact estimates (and some
 additional actual data) when this
 proposed regulation is promulgated, the
 very nature of predicting impact based
 on assumptions .and technical judgment
 dictates that impact estimates still be  .
 viewed in a relative sense., • "    ,    •

 3. Affected Industries   ,..  - .        .
"-•' • Since the proposed actiPn is chemical
 specific ratherthan industry-specific, it
. affects a'wide.range of industries. The
 following table (Table 2} shows the
 affected industries by Standard'
 Industrial Classification. (SIC) code, and
 gives the number of potentially affected
 facilities:                        •

   TABLE 2.—DIRECTLY AFFECTED INDUSTRIES
 TABLE 2.—DIRECTLY AFFECTED INDUSTRIES—
          "''<,', Continued
Industry
Plastics . • '
materials and
resins. * • -

Synthetic
rubber.


Medicinals and
botanicals.


Soap and other
detergents.




Surface active
agents.



Paints and
allied
products.
Cyclic crudes
and
intermediates


. Industrial ; <
Organic
chemicals. '
SIC ,
code
No.
2821



2822



2833



2841





2843




2851


2865

- -


, 2869

' Description -
Manufacturing pf . ,
synthetic resins,
plastics materials and
nonvulcanizable
elastomers. . ' ' .
Manufacturing synthetic '
.rubber 'by
polymerization or
copolymerization.
Manufacturing bulk :
organic and inorganic
medicinal chemicals . ,'
and botanical drugs.
Manufacturing soap and
synthetic organic.
detergents, inorganic
alkaline detergents.
and crude and refined
. . glycerin. "
Producing surface active
preparations as
wetting agents.
emulsifiers, and
penetrants:
Manufacturing paints'.
varnishes, and.allied
paint products. *
Manufacturing coal tar
crudes and cyclic
organic intermediates,
dyes, color lakes, and
toners.
Manufacturing, industrial
organic, chemicals not
• elsewhere' classified.
Affect- '
ed
facili-
ties1
823



2



1



2





22




2


'.' 185




•214

. Industry .
Agricultural
. chemicals. .




Petroleum
refining.


Nonferrous
wire drawing
and
insulating.

Total

SIC
code
No.
[2879


,11


J2911-
'•,' '
•i:
'i
3357


']
.;'•.-


.Description
Forrnulation and .'
preparation of pest. .
control chemicals.
including insecticides, .
. : fungicides, and •
' .hetbicides;
Producing' gasoline, -
kerosene, fuel oils.
. .lubricants, and other
petroleum derived
• products. ' ' :
Drawing, drawing and
. insulating, and
insulating-wire and ,
. cable of honferrous
metals. . .


Affect-
.ed
facili-
ties ' .
' 7'





2



.5




1;265'

  'Based on Alternative"2 (ioxdilutton/attenuation factor).

 Most of the plants "that produce and use
 the proposed chemicals appear in the
 organic chemical industries. Any facility
 that  is projected to generate a waste,
 which could produce a TCLP extract  ;   ,
 cpntaming ajiy .contaminant at.      ,
 concentrations greater^than the   -,
 regulatory level (i.e., the solubility of, the
 contaminant exceeds the level), is  ,  ,
-.-assumed to be a,hazardous waste. ;
 (Those wasites currently regulated by '
 RCRA are not included in the analysis.)
 The  number of affected facilities may
 include plants that produce or use more
. than one of the chemicals. The actual
 number of plants affected may therefore
 be less thani the1 total shown.
    The RIA addresses primarily the
" impact of the .expansion of the Toxicity
 Characteristic oh the industrial sector. It
 is apparent, however, that since sewage
 sludges are; defined as solid wastes  '
 - under RCRA, today's proposal will also  .
 have an impact oh the municipal'sector.
 '. Given that there are some 15,000
 municipal generators of sewage sludge
 across the United States, the impact
 could be significant. While less than 10
 percent of these facilities .accept ,
 sufficient industrial waste to cause any
 concern, these facilities generate most of
  the  sewage sludge across the United
  State's.    |      ... "~-      ;
    The existing and proposed regulations
  do not differ in their-treatment of metals.
  Thus, any impact of the proposed
  regulation on the municipal sector:
 .would be due.solely to the additional
 ' organic compounds. Due to this concern,
  EPA has begun a testing program to
  evaluate these sludges. To date, eight;
  sewage sludges from facilities receiving
  significant industrial input have been
  tested with the TCLP, and allwere
  found noUo exceed any of the Toxicity
  Characteristic levels (organics,or
  inorganics), Although more sewage

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 21662
Federal Register / Vol. 51. No. 114 /Friday, June 13, 1986 / Proposed Rule,s
 sludge is being tested, EPA expects that
 only sludge containing very high levels
 of the organic toxicants proposed for
 addition (which would most likely be
 introduced through industrial input),
 would be defined as hazardous. Very
 few sewage sludges are expected to be
 hazardous wastes.
   Hence, most of the impact of the
 proposed rule on the municipal sector
 will be the requirement to evaluate
 sludges against the Toxicity
 Characteristic levels. This, as explained
 earlier in the preamble, does not
 necessarily mean that all sewage
 sludges will be tested using the TCLP.
 Rather, as with the current EPTC, the
 vast majority of sewage sludge
 generators will perform that hazard
 determination using their knowledge of
 the sludge they generate. EPA believes
 that most of the municipal facilities
 receive such small amounts of industrial
 input, that they will be able to support a
 determination of non-hazardousness
 without having to test sludges using the
 TCLP.
   To assess more fully the regulation's
 impact on the municipal sector, the
 Agency will be collecting additional
 data during the period between proposal
 and promulgation. To help the Agency in
 its impact estimates, EPA is requesting
 that data on municipal sewage sludges
 generated with the EP, the TCLP, or total
 analyses be sent to the Agency.
 Although it is  not necessary to indicate
 the source of the sewage sludge, EPA
 solicit!; information such as the extent of
 industrial input to the generating
 facilit3', the type of industry involved,
 the amount of sludge generated by the
 facility annually, the type and extent of
 sludge generation and treatment (e.g.,
 primary, secondary, tertiary, filtration,
 etc.), and the disposal method used.
 4. Methodology Employed
   a Economic impacts methodology. A
 Partial Equilibrium Multimarket (PEM)
 model was used to estimate economic
 impacts. The basis of this model is the
 partial equilibrium framewo/k, in which
 only a manageable number  of markets is
 modeled. Economic impacts, or
 equilibrium changes, in non-modeled
 markets are assumed to be insignificant.
   Input, directly affected, and output
 markets ideally would be linked
 together by a vertical market structure.
 A majority of the expected market
 changes would be modeled by the
 structure in which markets are linked to
 each other through the purchase of
 inputs or the sale of outputs. As changes
 occur in one market, resource
reallocations by buyers and sellers
prompt changes in other markets.
Limited data availability imposes
                   "constraints on such a modeling effort.
                   Thus, the economic impacts model, used
                   quantitatively, projects economic
                   impacts only in the identifiable directly
                   affected markets.
                     As described in the full RIA, directly
                   affected markets have been identified at
                   the four-digit SIC level. Since different
                   products are included within a four-digit
                   SIC code, products unaffected by the
                   proposed regulation may unavoidably
                   be included in this analysis.
                     The directly affected markets are
                   linked together by means of the PEM
                   model. Data requirements include an
                  I original equilibrium, supply functions,
                   demand functions, and the initial
                  • impacts caused by the proposed
                   regulatory alternatives. Several
                  ; assumptions make this data collection
                   effort more manageable. Within this
                   economic impacts model, all supply
                   functions are  treated as being perfectly
                   elastic. This assumption limits the
                   interaction between directly affected
                  ^markets. A demand shift in an output
                   market does not change input price and
                   does not change production costs of a
                   directly affected product. What this
                   simplification implies cannot be
                   assessed because of limited data. In the
                   long run, however, all supply functions
                   tend to become more elastic (or flatten),
                   making the importance of this
                   assumption less significant.
                     Demand functions are assumed to
                   incorporate changes in equilibrium. As
                   defined by Just, Heath, and Schmitz
                   (Ref. 15), these general equilibrium
                  . .demand functions define the
                   relationship between price  and quantity,
                   given all changes in output  markets. For
                   example, a price increase and quantity
                   decrease in an output market ordinarily
                   will shift demand for a directly affected
                   product. With a general equilibrium
                   demand function, a shift in  demand
                   function does not have to be defined.
                     Market changes caused by the
                   proposed regulation are straightforward.
                   Initial equilibrium changes occur as
                   increased production costs  and cause
                   supply functions in the directly affected
                   markets to shift up. Owing to the
                  . assumptions listed above, .these new
                   prices and quantities now represent a •
                   new equilibrium since input prices do
                   not change and demand for directly
                   affected products does not shift.
                  , Changes in the unmodeled input market •
                   are only changes in quantity traded.
                   Changes in unmodeled output markets
                   are an increase in price and a decrease
                   in quantity traded.
                     The PEM model simplifies the
                   analysis in several ways. Most
                  ...importantly, it allows measurement of
                   all social costs in the directly affected
                   markets. Also, it allows the  economic
 impacts to be:solved in several steps
 rather than simultaneously. The
 projected economic impacts are then
 used to define benefits and costs..
   b. Benefits estimation methodology.
 Regulation of wastes containing any one
 of the selected chemicals is anticipated
 to result in a reduced risk of
 contamination of ground water that
 serves as a supply of drinking water for
 many communities. If the contaminating
 chemical is a carcinogen, consumption
 of drinking water may result in an
 excess incidence of cancer cases in the
 population. Ingestionpf noncarcinogenic
 chemicals in drinking water at a level
 above; the RfD may be correlated with
 toxic,:reproductive, or genetic effects,
 depending on the particular chemical. If
 people avoid drinking contaminated
 ground wa'ter, switching to  an  '
 alternative water source imposes
 substantial costs on the affected
 communities. Often, if a chemical  has
, been detected in the ground water, the
 contaminated aquifer is cleaned up (to  :
 the extent possible) and the landfill
 treated, which also results in  additional
 costs to the community.
 .. Estimates are made for each chemical
 of the health effects and switching and
 cleanup costs (corrective costs)
 attributable to the presence of that
 chemical in the ground water.
 Regulation of the waste  is assumed to
 prevent these'estimated health effects
 and corrective costs completely. The
 estimated benefits attributable to the
 regulation are .the health effects and
 corrective costs avoided by its
 implementation.
   Four steps are used to determine
 benefits: (1) Estimate quantity and
 concentration of chemical in landfill, (2)
 estimate concentration of chemical in
 leachate (i.e.. TCLP extract), (3) estimate '
 chemical concentration at drinking     -;
 water well, -and (4) estimate health
 effects and corrective costs  attributable '*
 to that ground water contamination.
  The unregulated wastes are assumed  •.,
 to be disposed in a landfill each year for
 20 year's (the average lifetime  of a
 landfill). The amount of the  chemical    :
 contaminant that leaches through the   .;
 landfill, and the leaching duration,  is
 determined using a leachate      '      :
 concentration model. From the bottom of
 the landfill, 'the contaminant is
 transported through the aquifer to the
 community well. The concentration of
 the contaminant at the well  varies over
 time and is tracked over 100 years  with
 a ground water transport model. The
health and corrective costs attributable
to  the contaminated well are then
estimated by a health and corrective .
costs, model.

-------

   Two methods—the Base Case Method
  (Alternative. 1') and an Alternate Method
  (use of a ground water transpoft'THOdel)
  were employed to estimate the •
  concentration of the chemical in the
  leachate at the well. The estimated
 ; benefits presented in the next unit are
  calculated using the Base Case Method.
  This method assumes (1) that the landfill
  receives predominantly domestic refuse,
r ^with only 5 percent of the landfill
  holding industrial waste, (2} that the
  character of the leaching fluid to which
  wastes are exposed is primarily a
  function of the non-industrial material in
  the landfill, (3] that the landfill is
  located over an aquifer that is a source
  of drinking water, (4) that the soil below
 : the landfill has limited attenuative
  capacity, (5) that the nearest drinking
  water wells are 150 meters (500 ft)
  downgradient  from the landfill, and (6]
  that as constituents migrate from the
  landfill through the urisaturated and
  saturated zones to the source of drinking
  water, they are attenuated by a factor of
  100.
     c. Cost estimation methodology. The
  current disposal costs, .pr.baseline, must
 . be established if the increased disposal
  costs, incurred,by waste generators due
  to the proposed regulation are to be .
  estimated. Current disposal costs are a
  function of the disposal alternatives in  ,
  use. Where the waste is not a listed
  hazardous waste,; current disposal
  practices are identified by examining
  the technical literature, by analogy to
  similar wastes for which disposal
  practice is known; or by assumption.
     Some baseline disposal .alternatives
  may understate the actual treatment and
  disposal applied to that waste, because
  no effort has been made to determine
  which wastes may be affected by State
  and; local regulations that, are .more
  stringent than Federal regulations. This
  may also, occur because firms
  voluntarily may be applying more   ;
  thorough treatment and disposal than
  required by regulation. The result of this
  potential understatement of baseline
   treatment and disposal, alternatives is
   that the estimated increase in disposal
   costs to comply with the characteristic
   approach will be greater than the actual
   increase.
     For currently landfilled wastes not
   listed as hazardous but subject to the
   regulation, disposal practice after
   regulation will become more stringent
  , and costs will increase. Disposal costs ,
   are assumed  to remain the same for
   wastes currently incinerated or  k
   deepwell injected. Solvent waste's and a
   few other wastes are assumed to be
   incinerated.     '. .''"''
     Using model plant information,  '
   estimates of the incremental disposal
 and operating and maintenance^ costs
Associated with the implementation of
*he alternatives are projected. These
 estimated costs are then compared to
 the cost of contracting, with commercial
 disposal services to.estimate properly
 the minimum costs incurred by the
 affected facilities. These costs are
 anmialized to reflect an accurate
 measure of the increased"production
 costs associated with this proposal.
 Estimates of percentage cost change are
 generated for use in the product/
 consumption model. Under the
 .assumption of full-cost pricing, these
 percentage estimates are determined by
 dividing the annualized incremental
 costs by the value of shipments in
 affected SIC industries.
   The economic impacts model is used
 to derive all costs or welfare losses
 borne by consumers of directly.affected
 products. Consumers suffer, a welfare
 loss because they lose consumer ,
 surplus, or the value placed, on
 consumption in excess of the amount
" required to purchase a product-..-
 Economic theory allows the estimation
 of total consumer costs;through impacts
 in the directly affected markets. Thus,
 input and output market data are not
 required.   . •'.   :, .
    Consumer surplus losses represent the
 only recurrent or annual costs. Changes
 in waste disposal methods in response
 to a regulation are represented by an
 upward shift in the supply function. The'
 higher production costs that result
 create a new equilibrium and a
  consumer surplus loss. The new
  equilibrium will have lower production
  at a higher,cost than the initial
 ' equilibrium^ A real resource cost is the,
  value of the additional.costs incurred to
  produce the new lower level of output. A
 - dead-weight loss is the loss in surplus
  value consumers placed^on those units
  that will no longer be produced.
    Extension of the above analysis to a
  multimarket situation is straightforward.
  Since impacts in input and output
  markets need not be considered, total
  welfare costs are developed by
  assuming:welfare costs in the directly
  affected markets.;
    Consumer surplus costs represent  .
  annual costs. Within this analysis all
  baseline data  are presented for the year
  1982. Consumer surplus losses will
  continue to be incurred, however, for an
  unknown number of years. To develop
  cost estimates for future years, costs are
  first estimated for 1982 and then
  assumed to be constant for all
  subsequent years. This simplifying
  assumption is necessary  since time
  constraints preclude the projection of
  market trends.      -        •
 ' • Implementation, costs., consisting of
 transaction'costs 'and employment '.
 losses, represent losses in welfare that.
 will be incurred only once'. Transaction
 costs represient the value of resources
 that would "be expended to 'determine if
 a waste stream is'to be regualated.
 These costs are based on an estimated
 cost of sampling and analyzing each
 waste stream by affected facilities.
   Employment losses occur since.goods
 and services are forgone when
 individuals are employed. Losses are
 based oh th|e projected change in
 production and employment-to-output
 ratios for each directly affected market.
 These losses are not valued in dollar
 terms becanise projecting the length of
 time for which an employee is,
 unemployed is difficult. Similarly, the
 value to place on tune, individual job
 skills, age, education, and personal
 dislike of being unemployed are not
 valued .in dollar terms.  ..   \   •  • '   -

 5. Results |
   o. Aggregate benefits. Continued use
 of current practices for managing wastes
 producing TCLP extracts  containing the
. selected chemicals in excess to -, .
; regulatory levels is expected to res, nit ia
 the deterioration of .environmental
 , quality. This deterioration may elevate
 risks to huitnan health and reduce the
 quality of environmental  resources, such
 as drinking water. The major route by
 which environmental quality is expected
 to be affected is through' the leaching of
 contaminated wastes into ground water.
 Over 50 percent of the U.S. population
 uses groun d water for drinking water.
 Further, contaminated ground water can
  enter surfatce water, reducing its quality.
 The capacity of both ground water and
  surface water to assimilate toxic
 ' chemicals is limited.  ,       -...,'•-
    If peoplts drink contaminated ground
  water, a wide range of health effects
  may occur, from simple gastrointestinal
  problems to cancer and birth defects;'
  The focus is on the possible excess
  cancer cases if the  selected chemicals
  are not regulated. It is assumed that
  contaminated water would continue to
'  be used as a drinking water source until
  the concentration reached taste or odor
  thresholds of the average person. When
  that threshold is attained, it is assumed
  they would switch to alternative water
  sources.  '.•,--.                    *
    When a landfill is recognized as a
  source of ground water contamination, it
  is also assumed that the municipality'
   would take action to prevent further
   leaching of the chemicals. Estimates
   were developed for a representative
   community arid aggregated' to pbtain ;
   national totals. This aggreation process

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  21664
Federal Register / Vol. 51, No. 114 /Friday. June 13, 1986 / Proposed Rules
  is not very precise, so the reader is
  cautioned to interpret the results
  presented carefully. The benefits and
  costs for each regulatory alternative are
  summarized in the following table
  (Tables).

     TABLE 3.—BENEFIT-COST ASSESSMENT
Elonafits-Costs
Monetized benefits*
Avoided cost of alternative
watof source:
Prosem value (S10*)* 	 ..
AwKulized (S10«/Yr) 	
Avoided cosl o» aquifer
cteamjp;
Present value (S10«)» 	
Annutiftzed (SIO'/Yr),.., 	
Monetized costs;
float rosoiHco cost:
Present value (S10»)*__...._
Annwiitzcd (S10»/Yi)_, 	
Deadweight consumer sur-
pktscosl:
Present value (S10«)k 	
Annunllzed (S10*/Yr).™...._..
Transaction cost (S10«)< 	
Net monetized benefits:'
Present value ($10")' 	
Armu»feod (SIOVYr) 	
Nonrnonotzod benefits;1
AvoKtod cancer cases. 	
Avoided person-years of ex-
pojoro above tha chronic
ttxoshould (10») 	
Konmomtized costs;
Employee dislocations — 	
Regulatory alternative
1



3,218
378


11.897
1.398

1.285
151


1.2
0.1
12

13,830
1,625
54


4.8

407
2



3,317
390


12.316
1.447

1,287
151


1.2
0.1
1.2

14.345
1.685
, 54


4.8

407
3



3,174
373


11,719
1,377

1,186
139


1.0
0.1
1.2

13,706
1,610
53


0

372
  •Bonofitt are based on Alternative 1.
  * 20-Year cost discounted at 10 percent.
  'One-time cost incurred fust year.
  'Monetised benefits  minus monetized costs excludina
 transaction costs,                           s

   These estimates of the health effects
 and corrective costs attributable  to a
 waste are developed for a typical
 community. The estimates of the
 aggregate benefits of the proposed
 regulation are obtained by assuming
 that health effects and corrective costs
 would be avoided by all the
 communities affected by the proposed
 regulation. Since the aggregation
 process used assumes that each waste
 affects a single typical community, it is
 somewhat arbitrary. Again, the reader is
 cautioned to interpret results with care.
  b. Aggregate costs. Benefits of the
 regulatory alternatives would be
 accompanied by costs. As described
 previously, total costs of the regulatory
 alternatives includes real resource costs,
 dead-weight consumer surplus losses,
 dead-weight producer surplus losses
 (capital value losses), employee
 dislocation costs, and transaction costs.
Two of these welfare costs have not
been projected  in this analysis.
Employee dislocations have been
quantified, but their social costs have'
not been evaluated. Capital value losses
incurred by owners of affected capital
also have  not been evaluated.
  c. Benefit-cost comparison. Most
public policy alternatives have benefits
and costs. Policy'evaluation can be
                    difficult because these benefits and •
                    costs typically accrue to different    %
                    individuals. Harberger (Ref. 11) has.
                    argued that:
                    when evaluating the net benefits or costs of a
                    given action (project, program, or policy), the
                    costs and benefits accruing to each member
                    of the relevant group (e.g., a nation) should
                    normally be added without regard to  the •
                    individuals to whom they accrue.

                    This principle dates to Kaldor (Ref. 16)
                    and Hicks (Ref. 12), who argued that a
                    change should be instituted if a potential
                    gain exists so that those  who bear the
                    cost could be compensated fully for their
                    loss by the beneficiaries, and the
                    beneficiaries would still be better off
                    than before. Following the Kaldor-Hicks
                    principle, this RIA evaluates benefits
                    and costs to society at large without
                    regard to their incidence.
                      Table 3 summarizes the benefits and
                    costs of the regulatory alternatives. The
                    difference between the monetized
                    benefits (i.e., avoided corrective costs)
                    and monetized costs (i.e., real resource
                    and dead-weight consumer surplus
                    costs) is compared using  the annualized
                    method. This difference is positive for
                    all regulatory alternatives. Thus, each
                   alternative would provide an
                   improvement in economic welfare.
                     An evaluation of the regulatory
                   alternatives will allow a comparison of
                   the different regulatory levels for the
                   proposed contaminants. Moving from
                   Alternative 2 to 1, respectively leads to
                   virtually no changes in health benefits,
                   but does increase the net monetized
                   benefits by $61 million per year. This
                   suggests that Alternative  2 is preferable
                   to Alternative 1. Moving from
                   Alternative 3 to 1 leads to substantial
                   reduction in health benefits, and yields a
                   decrease in net monetized benefits of
                   $14 million per year.
                    As explained earlier, this RIA
                   compares the benefits and costs of
                   several regulatory alternatives that were
                   determined by multiplying estimated
                   chronic toxicity reference levels for the
                   selected compounds, by assumed
                   dilution/attenuation factors of 10,100
                   and 1,000. This was necessary, as the
                  •toxicity reference levels and the model-
                   generated dilution/attenuation factors
                   that were proposed today could not be
                   generated in time for this analysis.
                   Hence, while this analysis provides
                   estimates of the range of regulatory
                   impacts due to the proposed rule, it does
                  not directly provide an estimate of the
                  impact qf the proposed rule. The final
                  RIA which, will accompany the
                  promulgation of this rule will analyze
                  the benefits and costs based on the final
                  regulation.
  B. Regulatory Flexibility Act

    Under the Regulatory Flexibility Act, 5
  U.S.C. 601-612 whenever an Agency is
  required to issue for publication in the
  Federal Register any proposed or final
  rule; it must prepare and make available
  for comment a Regulatory Flexibility
  Analysis which describes the impact of
  the rule on small entities (i.e., small
  business, small organizations, and small
  government jurisdictions), unless the
  Agency's Administrator certifies that the
  rule will not have significant economic
  impact on a substantial number of small
  entities'.                  -
    The Agency has examined the
  proposed rule's potential impact on
 'small businesses,  and has concluded
  that this regulation will not have a
  significant impact on a substantial
  number of small entities. Again, for the
  reasons stated in the above section, this
  analysis does hot  directly provide an
  estimate of the impact of the proposed
  rule on small businesses.
    More than 20 percent of the small
  firms in an industry is considered a
  substantial number of affected firms.   •
  This analysis uses a worst-case
  approach and assumes that all affected
  facilities belong to small firms. Three
  standard measures suggested by EPA
 guidance are used in determining a
• significant impact  on small firms within
 an industry. These are (1) when
 annualized compliance cost as a
 percentage of. total costs of production is
 greater than 5 percent, (2) when capital
 costs of compliance represent a      .
 significant portion of capital available to
 small entities,  and (3) when annualized
 compliance cost as a percentage of sales
 for small firms is more than 10 .
 percentage points higher than
 annualized compliance costs as a
 percentage ,of sales for large firms. For
 the purposes of this analysis, the costs
 associated with the first regulatory
 alternative  are used in assessing the
 significance of impacts on the small
 firms within affected industries.
   In determining the ratios needed for  '
 the third measure, annual compliance
 costs for each industry are apportioned  -
into two groups. One group is used with
the receipts for large firms and the other
is used with receipts for small firms. The
proportion going to each  group is equal
to the percentage of small and large
firms above and below the size standard
of 50 employees. EPA has elected not to
adopt the Small Business .
Administration's definition of small
business, which is fewer  than 500
employees for most SICs, because it
would include the majority of plants in
•the regulated community. Using a

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                     Federal Register /Vol. 51, No. .114 / Friday/June 13.1986 / ProposedRules
                                                                        31665
 threshold value which includes a
 majority of the total population obscures
 any differential impacts on smaller
 firms.- The Agency considers a, threshold
 value of fewer than 50 employees to be
 a more sensitive index of impacts on
 small businesses..
   For the other two measures, the entire
 cost for the industry is compared to the
 aggregate  data for small firms as a worst
• case. This will provide an extreme
 estimate ,of the number of industries that
 have small firms that might experience a
 significant impact.  A "significant portion
 otcapital available to small entities"  •
 depends on the average annual portion
 of new capital expenditures spent on
 pollution abatement in the last 10 years.
 If capital costs as a percentage of new  '
 capital expenditures are more than 10
 percentage points larger than the
 average percentage, that' has been spent
 in the last 10 years, than the capital
 costs are determined to be significant.
   Under this analysis, no SICs are
 impacted significantly by any of the
 three measures described. Accordingly, I
 certify that this proposed regulation will
 not have a significant economic impact
 on a substantial number of small     •
 entities. This regulation therefore does
 not require a Regulatory Flexibility .-'••>..
 Analysis.    .       •                ,

 C. Paperwork Reduction Act
   The proposed rule contains
 information collection requirements
 subject,to OMB review under the -  •
 Paperwork Reduction Act of 1980, 44
 ' U.S.C. 3501 et. seq. Specifically, under 40
 CFR 262.40, generators are required to
 keep records on how the hazard   .
 determination was made for the wastes
  they generate. EPA believes that these
 information collection requirements are
  insignificant arid has not prepared
  documentation pursuant to the
  Paperwork Reduction Act. If necessary,
  such documentation will be prepared for
  the promulgated rule.
  VIII. Additional Information
  A.  Chronic Toxicity Reference Levels_
  1. Introduction        '
    When the EP Toxicity Characteristic
  (EPTC) was promulgated in May of 1980,
  the only standards which existed for
  establishing toxicity levels, and which  .
,  addressed chronic exposure, were the
  National Interim Primary Drinking
  Water Standards  (NIPDWS). These, '
  addressed 8 metals, 4 insecticides and 2
  herbicides, and hence, EP toxicity
  thresholds were limited to these 14
  contaminants. Today, however, chronic
  toxicity levels have been established for
  a mimber of additional toxicants. This
  Section provides details on the chronic
 toxicity reference levels which are being
 proposed for use in, expanding the
 Toxicity Characteristic.  ;    .

 2. Non-Carcinogenic Constituents
   Establishing regulatory levels for  '
 individual contaminants requires the
 initial input of a health reference level.
 Determination of the appropriate level is
 dependent upon the nature of the toxic
 effect of the constituent, specifically
 whether, or not the constituent is a
 carcinogen. Substances which dp' not
 cause cancer exert toxicity through
 mechanisms which exhibit physiological
 thresholds. Thus a reserve capacity,
 assumed to exist within an organism,
- must be depleted or overwhelmed
 before toxic effects are .evident. Simply -
 put, for each non-carcinogen there is
 some low level of exposure which has
 no effect on humans. Protection against
 'a chronic toxic effect-for a non-
 carcinogen is achieved by keeping
 exposure levels at or below .the
 reference dose.
   For non-carcinogenic constituents, the
 Agency is proposing to use Reference
 .Doses (RfDs) as the starting point for
 establishing chronic toxicity regulatory
 levels.. An RfD is an estimate,of a
 lifetime daily exposure of a substance to
 the general human population, which
 appears to be. without an appreciable
: risk of deleterious effects. Conceptually,
 the RfD is closely related to the term
 Acceptable Daily Intake. ADIs were first
 used-by the Food and Drug
 Administration (FDA) in 1954 as specific
 guidelines and recommendations on the
 use of "safe" levels of chemicals, such
 as food additives or food contaminants,
 for human consumption (Ref. 18). Since
 their initial use by the FDA, ADIs Have
 been used by other public health
 agencies in establishing "safe" levels for
 toxic chemicals. The Food and
 Agricultural  Organization, World Health
 Organization, and EPA have used ADIs,
 in the process of establishing allowable
 pesticide residues in foodstuffs (i.e.,
 tolerances). The National Academy of
 Science  and EPA have ^estimated ADIs
 for purposes of establishing safe levels
  of contaminants in drinking water (Ref.
  30).       '
    The experimental method for
  estimating the RfD is to measure the
  highest test dose of a substance which
  causes no statistically or. biologically
  significant effect in an. appropriately
  conducted animal bioassay test. This
  experimental no-observed-adverse-
  effect-level (NOAEL) is an estimate of
  the animal population's physiological
  threshold. The RfD is derived by.
  dividing the NOAEL by a suitable
• scaling or uncertainty/factor.
   NOAELs are usually obtained through
 a chronic study pr a :90-day subchronic
 study. Other available lexicological  .
 data, such as metabolism and   ..-..•.    .
 pharmacokinetics, are used to validate
 the judgmental choice of a particular
 dose level as the.NOAEL. Confidence in
 the NOAEL,  and therefore injhe RfD, is
 dependent on the equality of the     "    .
 experiment,  the number and type of
 animals tested at each level, the number
 and range of dose levels, the duration of
 the study (i.e., chronic vs subchronic),
 and the nature of the biological endpoint
 measured'{i.e., the severity of the
 observed effects). The longer the
 duration of the study, the smaller is the
 uncertainty'factor applied to the
 NOAEL; Selection, of the appropriate
 uncertainty factor 'involves scientific
 judgment and the application of general
 guidelines.'(Ref. 30). The derivation of
 RfDs used for establishing regulatory
. levels has been evaluated and verified
 by an Agency workgroup (Ref. 3.0, 31,
; and 32).  | • .  -        X  ^ -. . , /"   ~
   Table A-l presents the"propbsed non-
 carcinogensLand their RfDs. The RfDs in
 this'table aijie calculated by assuming
 that a 70 Kg person ingests the
 compound in 2 liters of drinking water.
 per day.  - i .           .

   TABLE A-1 .—NON-CARCINOGENS AND RFDS
         .-  !     (MG/L)  .
. •: Compounds
Carbon disulfkfe.i -, -
Chlo'robenzene. l
o-Cresol ;
m-Cresol >
p-Cresol, - *
1,2-pichlorobenzene.
IsobutanoK
Methyl ethyl ketcme.
Nitrobenzene. ' ,
Pentachlorophenol
Phenol - ~ -
Pyridine ~ -
2,3,4,6-Tetrachlorophenol:
Toluene. 	 	 -
2.4,5-Tfichlorophenol .
RfD '
4
J
>2
'2
'2
3
MO
2
0.02
.1
4 . .
0.075
'0.4 •
10
4
   1 Preliminaty estinia'te of RfD. .

   For some of the contaminants    •
  addressed in today's proposed rule,.   ,
  insufficient toxicological data exists for
  establishing an RfD. EPA is using      .
  preliminary data for isobutanol, ortho-,
  meta-, andpara-cresol, and 2,3,4,6?-
  tetrachlorophenol while appropriate
  testing continues. The Agency will
  revise these RfD's and repropose the
  regulatory .levels if necessary. Note also
  that the Agency intends to propose   . . .
  regulatory levels for nickel and thallium
  during the period betweeri-proposal and
  promulgation of this rule. The chronic
  toxicity levels for nickel and thallium
  are expected to be 0.15 and 0.002 mg/1,
 : respectively.;    ;   ' .

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   21666
Federal Register / Vol. 51, No. 114 / Friday, June 13, 1986 / Proposed Rules
   3. Carcinogenic Constituents
     The use of the RID is appropriate only
   for non-carcinogenic toxic endpoints. In
   the absence of chemical specific
   information on mechanism of action or
   kinetics, EPA science policy suggests
   that no threshold dose exists for
   carcinogens. No matter how sma.ll the
.   dose, some risk remains.
     The dose-response assessment for
   carcinogens usually entails an
   extrapolation from an experimental high
   dose range and observed carcinogenic
   effects in an animal bioassay, to a dose
   range where there are no observed
   experimental data, by means of a pre-
   selected dose-response model. The slope
   of the dose-response curve is
   determined by this model. EPA's
   Carcinogen Assessment Group has
   estimated the carcinogenic potency (i.e.,
   the slope of risk versus exposure) for
   humans exposed  to low dose levels of
   carcinogens. These potency values
   indicate the upper 95 percent confidence
   limit estimate of excess cancer risk for
   individuals experiencing a given
   exposure over a 70 year lifetime. In
   practice, a given dose multiplied by the
   slope of the curve gives an upper limit.
   estimate of the number estimated to-  .
   develop cancer. The slope can be used
   to calculate the upper limit of the dose
  which gives rise to a given risk level ,
  (e.g., one response in a hundred
  thousand). By specifying the level of risk
  (no matter how small) one can estimate
  the lifetime dose corresponding to it.
  The upper limit of the dose of a
  carcinogen corresponding to a specific
  risk level is called the Risk Specific
  Dose (RSD). To arrive at a starting
  health limit for a carcinogen, a risk level
  or range of concern must be specified. •
  EPA proposes to specify a risk level of
  concern on a weight-of-evicjence basis,
  as described below.
    In November 1984, EPA proposed
  Guidelines for Carcinogen Risk
  Assessment (49 FR 46294), which
  described a scheme to characterize
  carcinogens based on the experimental
  weight of evidence. This scheme is
  based on considerations of the quality
  and adequacy of the experimental data
  and the kinds of responses induced by a
  suspect carcinogen. The classification.
  scheme is generally an adaptation of a
  similar system developed by the
  International Agency for Research on
  Cancer (Ref. 13).
   EPA's classification of weight-of-
  evidence system comprises five groups.
  Group A indicates  human carcinogens.
 This classification  is based on sufficient
  evidence from epidemiological studies
 of a causal association between human
 exposure to the substance and cancer.
                    Group B indicates probable human
                    carcinogens. The evidence of human
                    carcinogenicity from epidemiological
                    studies for substances within this group
                    ranges from almost sufficient to
                    inadequate. This group is subdivided
                    into two categories (Bi and 62) on the
                    basis of the strength of the human
                    evidence. Where there is limited
                    epidemiologic evidence oL  '
                    carcinogenicity,  the carcinogen is
                    categorized as Bi. Where there is no
                    evidence or inadequate evidence from
                    human studies, the carcinogen is
                    categorized as Ba. Group C comprises
                    possible human carcinogens. This group
                    includes agents with limited evidence of
                    animal carcinogenicity. It includes a
                  •  wide variety of animal evidence. Group
                    D includes agents which cannot be
                    classified because no data or
                   insufficient data  are available. Group E
                   includes chemicals for which there are
                   adequate negative animal bioassays.
                   This category indicates no  evidence of'
                   carcinogenicity in humans.
                     The Agency regards agents classified
                   in Group A or B as suitable for
                   quantitative risk  assessment. The
                   method for quantitation of  Group C
                   substances is best judged on a case-by-
                   case basis, since  some Group C agents
                   do not have a data base of sufficient
                   quality and quantity to perform a
                   quantitative carcinogenicity risk
                   assessment.
                    Since carcinogens differ in the weight
                   of-evidence supporting the hazard
                  assessment, EPA  believes that  ,
                  establishment of a single across-the-
                  board risk level is not appropriate. The
                  Agency proposes  to set a reference risk
                  level as a point of departure, along with
                  a risk range keyed to the weight of
                  evidence approach. The dose for known
                  and probable human carcinogenic
                  agents (Classes A'and B) would thus be
                  determined at the 10~5 risk level.
                    For the Class C carcinogens (agents
                  with less firm evidence of human
                  carcinogem'city), a risk level of concern
                  of 10~4 is being proposed. For those
                  Class C carcinogens for which there is
                  insufficient data to perform  a
                  quantitative risk assessment, the dose is
                  calculated pn.the basis of th'e lowest
                  threshold effect, with an .additional
                  uncertainty factor of ten (e.g., NOAEL/
                  1000). This approach is similar to the
                  approach taken by the Agency on
                  November 13,1985 in its proposed'
                  regulations on enforceable standards for
                  volatile organic chemicals in drinking
                  water (50 FR 46880). The Agency solicits
                  comments on the proposed risk levels
                  and the criteria for distinguishing among
                  the Class  C carcinogens for this purpose. '
    Some agents appear to cause cancer
  by only one route of exposure or entry.
" Conclusions about route specificity can
  only be addressed in circumstances
  where adequate data exists on
  carcinogenicity for more than one route
  of exposure. Where carcinogenicity
  findings are available from only one
  route of exposure, the substance is
  judged to represent a cancer hazard by >
  all routes, unless it can be scientifically*
  demonstrated that the material cannot
  gain access to target sites by the
.  alternative routes of interest. Where the
  data from one or more routes'are
  limited, the  Agency will evaluate each
  case on it's merits, placing particular
  emphasis on the scientific evidence.
    For a few substances (notably metals),
  the data base demonstrating that cancer
  is produced by one route of exposure  '
  but not by another is substantial and
  convincing.  An example of a substance
  whose carcinogenic response is
  characterized as route-specific is
  chromium and some of its salts. These
  substances cause cancer by inhajation
  but not by other conventional routes of
  entry. The Agency will regulate such
  substances as carcinogens only by the
  relevant route and as non-carcinogens
  by all other routes.
   Table A-2 presents those proposed
 Toxicity Characteristic contaminants
 that are carcinogens, the class of the
 carcinogen, and the Risk Specific Dose.

  TABLE A-2.—CARCINOGENIC CONTAMINANTS
             AND RSD (MG/L) l  " -  ,
Contaminant
Acrylonitrile 	
Bis (2-chloroethyl)
ether.
Chlordane 	 .:.....
Chloroform 	 	
2,4-Dinitrotoluene...
Heptaohlor
Hexachloroben-
zene.
Hexachlorbuta-
diene.
Hexachloroethane...
Methylene chloride .
1,1,1,2-
Tetrachloroeth-
ane.
1.1.2,2- ' , • '
Tetrachloroeth-
ane.
Tetrachlorbethy- ••
lens. , .
1,1,2-
Trtchloroethane.
2,4,6- •
Trichlorophenol.
Carcinogen
class
B;.
B
C 	 .;. 	 -. 	
B
B 	
B <
B .:...;.... 	 : 	
c 	
C 	 '
B .
C 	 	
c 	 .., 	 „..
B
c.. 	
B . • '

Risk
level

•JO"6
10-'
10~5
10~s

10^B
10"*
• 10~4
10~s
- 10" *
, .io-«
10~5
10~4


Risk specific
dose (RSD)

3E-4
2E-3
1E-3 r

2E-4
5E-2

6E-1
7E-1
2E-2,
7E-3 "' ' ; " •
6E-2


  Does not include those carcinogenic, contaminants for
which Dnnkmg Water Standards have been established or
proposed (See next section).   ,   •....••

4. Use of Existing Agency Health
Standards

  Under the existing EP Toxicity
Characteristic, EPA uses the existing

-------
                     Federal-Register ):Vol. 51, No. 114 / Friday. June 13,1986 / Proposed Rules
                                                                       21667
 National Interim Primary Drinking
 Water Standards, established for eight
 elemental contaminants and six'    .,   .
 pesticides, as toxicity thresholds.
 Today's rule retains these thresholds for
 the elemental toxicants but proposes
 compound specific dilution/attenuation
 factor based thresholds for the organic
 compounds.            '      .
   EPA has. also been working to..
 establish Drinking Water Standards for
 additional organic compounds. Final
 standards for drinking water, the
 Maximum Contaminant Levels (MCLs),
 are enforceable and are based upon
 health, treatment technologies, costs,
 and other feasibility factors such as the
 availability of analytical methods. The
 MCLs are set following an analysis
 based on health considerations as
 guided by the Safe Drinking Water Act.
 This intermediate analysis results in
 proposed Recommended Maximum
 Contaminant Levels (PMCLs), which are
 non-enforceable health based limits.
 Included  in the analysis of the health
 considerations for determining PMCLs  '.
 are not only the quality and weight-of-
 evidehce of the supporting toxicological,
 studies, but also examination of
  absorption rates of specific toxicants,
 the possibility of nutritionally essential
 levels for some elements, the existence
  of route-specific toxicity, the
  demonstration of other environmental
  exposures, and finally, the
  apportionment of the permissible limit of
  constituent into media specific amounts.
  In general, final MCLs for noft- ,
  carcinogens are based on 20% of the
  relevant  RfDs, to account for exposure
  from other sources (e.g., food and air).
  Final MCLs for carcinogens are based
  on risk levels that range from 10 ~4 to
  10"6-    .      •
    Since the above factors have been
  evaluated for each of the  other .
  contaminants in today's_rule, PMCL ,
  standards derived under the Safe
  Drinking Water Act can be used as. . ..
"' toxicity thresholds. On November 13,
  1985 EPA proposed MCLs for eight
  synthetic volatile organic chemicals (50
  FR 46880). EPA is also proposing to use
  these contaminants and their proposed
  MGLs, which appear in Table A-3, as
  toxicity  thresholds for the Toxicity
  Characteristic. After public review and
  evaluation EPA will promulgate final
  .standards. Should the final MCLs differ'.
  from the proposed MCLs, EPA will base
  regulatory levels fof the Toxicity
   Characteristic on these revised final
   standards.
TABLE A-3.—PROPOSED MCL's FOR VOLATILE
       ORGANIC COMPOUNDS (MG/L)
* Contaminant
Benzene .....
Carbon tetrachlorlde.
1 ,4-Dichlorobenzene.
1 ,2-Dichloroethane.
1,1-Dichloroethylene
1,1,1 -Trichloroethane.
Triohloroethylene
Vinyl chloride.
Proposed
MCL .
0.005
0.005.
0.75
0.005
0.007
0.2
0:005
0.001
5. Apportionment of Health Limits
  The reference dose for humans is the
maximum daily dose of a substance tha't
should not be exceeded to assure no
adverse health effects over a lifetime of
exposure. If exposure occurs by multiple
routes, some tolerance level can be
established for each route so that the
sum of exposures by the individual
routes does not exceed the reference
dose.   ,          .-•'..
  The concept of apportionment of a
chemical by medium and by.route of
exposure is not new. The National
Research Council's Safe Drinking Water
Committee, calculated a suggested no-
adverse-response-level (SNARL) for
chronic exposure to a non-carcinogen in
drinking water, while incorporating an
"arbitrary assumption" that 20 percent,
of the intake of the chemical was from
drinking water (Ref. 20). EPA, in setting
PMCLs for chemicals in drinking water,
has followed, the suggestion of the NRG,
and selected a'fraction of the RfD,
usually 20 percent for synthetic organic'
chemicals if no empirical data suggest
some other fraction is more appropriate
(50 FR 46880, Nov. 13,1985). EPA is
proposing to apportion non-carcinogenic
contaminants according to the scheme
outlined on the following pages.
   In evaluating carcinogens,- the
National Research Council's Safe
Drinking Water Committee estimated
 cancer risks assuming that tap water
 exposure was both 1 and 20 percent of
 the total daily intake (Ref. 20). The
 Agency is however, not proposing to
 apportion the RSD for carcinogens. For
 such substances, the RSD is estimated
 by a procedure which introduces
 unavoidable uncertainties. The
 procedure used is deliberately
 conservative, so that a 'difference in
 dose of a factor of two is still well
 within the .margin of uncertainty of the
 estimated RSD.
    Moreover, for carcinogens, the   ,
 determination of risk is the daily dose
 averaged over a lifetime. Small,
: variations around the daily ;dose have
 little effect on the lifetime risk, providing
that the average is riot affected. For this
rea'sqn, a two-jfold'reduction in the RSD
is relatively insignificant. For non- .
carcinogens, it is possible that not
applying a 50 percent reduction (the
indirect effect of which is to permit an
approximate doubling of the RfD), may
cause the level to be exceeded on some
.or even many  iiays of exposure.
Exceeding the level for non-carcinogens   •
may therefore have significant health
consequences for some individuals.
Thus, there  is  justification for treating
non-carcinogens differently from
carcinogens with respect to
apportionment
  In the process to developing drinking
water standards, EPA considers the
contribution from other sources of
exposure, such as air and food. When
sufficient data are available, the PMCL
is determiried.by subtracting the known'
 contribution of the constituent in food    '
 and air from the RfD. Such data is often
not available. In these cases, the amount
 permitted in drinking water is calculated  '
 by an estimation of the percentage of
 exposure attributable to the exposure
 route of concern. In the absence of
 adequate exposure data, apportionment
 is established:at 20 percent for synthetic
 organic chemicals. For inorganic
 chemicals,  an adequate data base
 generally exists/The actual contribution
 from other  sources can be factored into
 the PMCL.  Where actual data is sparse,
 however, a W percent contribution is
 estimated for inorganics in drinking
 water, since sources other than drinking
 water are more likely carriers for
 inorganics.  '"
 -  Apportionment has also been used in
 the risk evaluation procedure developed  .
 for EPA's Office of Emergency and '
 Remedial Response to evaluate and
 manage the ri sks for specific remedial
 action sites under the CERCLA
 (Superfund) Law. In this procedure,   :
 concentrations are generally
 apportioned equally in environmental
 media (e.g., air and water), as an initial
 basis for calculating a rate of release. If
 there are significant cost and feasibility
  differences in controlling exposures via
  the different  pathways, unequal'
  apportionment is selected. This .option is
  appropriate under the CERCLA statute   ,
  since cost-effectiveness is an integral
  part of the decision-making process (Ref.
  5).          i'     •
    Many of the  chemicals EPA regulates
  are ubiquitous in the environment and
  may be associated with exposures from
  other media  (e.g., water, food, air).   ,
  Although available scientific.and   ;
  technical information as well as past

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 21668
Federal Register /.Vol. 51, No. 114 / Friday, June 13, 1986 / Proposed Rules
 decisions will be considered in reaching
 decisions on the apportionment of RfDs,
 sufficient information is not generally
 available on exposure to reliably
 quantify the proportion of the RfD that
 should be allotted for each chemical.
 When adequate exposure data does not
 exist, the Agency is proposing to limit
 population exposure to a 50% fraction of
 the RID to reflect consideration of
 potential and actual exposure from other
 media,
  EPA proposes to apportion reference
doses according to the scheme shown in
Figure A-l.
BILLING CODE 6560-50-M

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              Federal Register / Vol. 51, No.'114 / Friday, June 1£»J986 /JProposedBules
                                Figure A-l

                   Flow Chart for Apportionment of RfD
 Determine
 total RfD
Is there a
MCL for the
 compound?
-yes-
Has EPA
fractionated
RfD into  .
other media?
                    ••——yes---—
Fractionate RfD
according to EPA's
scheme.
                        no
     no
      Do data exist
    regarding concentration
    of .compound in the
    various media?
                                          —yes—
                              MCL-—crater
                              (100% of total RfD
                              MCL)-—fractionate
                              other media on a
                              basis.
                       minus the
                       to air -and
                         i-by-case
                                                                    c=se
                          no
                      MCL	water     '       -
                     (50% of.total RfD minus the
                      MCL)——air
      Do data exist  .
 regarding concentration of
   the compound in the
      various media?
               •—--yes——'
                     fractionate RfD- on
                    . a case-by-case  basis
      no
  50% of total RfD	to be fractionated
  to air and water using the volatility  and
  octanol-water constants
BILLING CODE 6560-50-C
                                                                      21669

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  21670
                      Federal

    Basically, (his scheme indicates that,
  if the Agency has adequate data to
  nssess exposure from various routes,
  then such data will be used to apportion.
  If on the other hand, adequate data
  does, not exist, EPA will use 50 percent
  of the RfD and subtract from this 50%
  the fraction of the RfD allotted to water,
  using the remainder for air.
    EPA proposes  to estimate
  environmental partitioning to air and
  water according  to a simplified scheme
  using Henry's Law Constant (HJ and
  the octanol-water partition coefficient
  (k0 J for individual contaminants.
  Henry's Law constant estimates the
  ratio of a substance between the vapor
  and dissolved (aqueous) state. The kow
  estimates the distribution of a
  compound between water and octanol,
  where octanol is  intended to represent
  an organic (lipid) component. Each
  distribution constant (Hc and kow) is.
  subdivided into two equal parts
  according to its range of values, as
  shown in Table A-4. Each contaminant
  to be apportioned is classified as having
  a high or low value according to the
  general size of its distribution constants,
  as shown iri Table A-5. A relationship
  between He and kow and the distribution
  between air and water has been devised
  using a matrix, as shown in Table A-6.

  TABLE  A-4.—RANGES AND  CLASSIFICA-
    TION  OF  HENRY'S LAW CONSTANTS (KH)
    and  Octanol-Water  Partition  Coeffi-
    cients (kow)                •
kH. 	
K™ 	
High in Air >10~5
Low in water >500....
T — -A- — 7""""
High in water
<500.
   TABLE A-5.—HENRY'S LAW CONSTANTS AND OCTANOL-WATER PARTITION COEFFICIENTS FOR
                          NON-CARCINOGENIC CONTAMINANTS
Contaminant
Catbon diwlfida., 	 , 	 , 	 , 	 ,
Chtofoberacne. ,„ „, ~
Cf&SOlS- ^ tl ..... «...
LZ-DtehtototxinxiHW 	 „ 	
totxrtano). ....... „„».„_„...„"
Methyl «thy»,k«an«., 	 	 	 	 „ 	 	
fiifiabtruemi.,.,,....,,.. 	
PwMSKhtotopbanol .„.....„„„,_.....„ 	 ..... .
Pt>eool.!,«,™,..m_,...,,,..ra._...._,m__M.-.i ., , "
Pyrxfcw , ,„.,.,., 	 „ 	 	 , .
J.3A6-T«*acMo«sph0
1.68E-02



2.61 E-05
4.62E-06
5.02E-06
1.95E-07
4.53E-06
5.93E-03
2.84E-05
Relative
concentra-
tion in air
High 	 	
High 	


High 	
High 	 	
Low 	
Low
Low 	 ...„..„„
Low 	
High 	
High 	
Octanol-
water
coefficient
(Kow)
1.45E+02
7.41E-f02
1.41E+02

,.2.00E+00
7.94E+01
1.15E+05
4.79E.+00
2.14E+04,
661E+ 02
7.24E+Q3
Relative
concentra- ,
tion in water
High.
LOW.
High, -..:

High.
High.
Low. , .
High; '
Low.
Low
Low.
 TABLE A-6,—DISTRIBUTION MATRI'X'BETWEEN
    WATER AND AIR USING KOW and k,, Air»

Wal«'
law,..,,.,,,,,.,,
H-sh...,™.
Low
A»,w«t8f 50:50 	 „„.
Arwater 20:80, 	
High
Ainwater 80:20.
Air.water 50:50.
              5
                   'aoural °* computed k,, and k..
  To construct the matrix, EPA assumed
 that a compound with equal ranges of
 kow and Hc {i.e., high-high or low-low),
 will distribute between air and water
 into equal parts. For compounds that
 exhibit a high range for Hc and a low
range for kow, EPA assumes that the
distribution would be in a ratio of 80  to
20, air to Water. As an example, given
lha t SO percent  of the total RfD is
available for apportionment into water
and air, and if Table A-5 indicates a
high Hc and a high kow,  the fractionation
of the total RfD is 25 percent of the total
RfD into each medium. If the
conlaminant exhibits a low Hc and a
high kow, then 10 percent of the total RfD
 will distribute to air and 40 percent to
 water.
   EPA believes that the approach
 outlined above is reasonable in light of
 the difficulty in obtaining exposure data
 for many compounds within the
 statutory time limit. The Agency solicits
 comments on this general approach. The
 Agency is also considering a simpler
 scheme which examines relative
 concentrations between water and air
 using Henry's Law constant only.
   Table A-7 presents all 52 compounds
 included for toxicity, their respective
 health based toxicity thresholds, and the
 results of any apportionment.1 The
 Tables in section VIII(C) contain further
 information used in establishing the
 proposed regulatory thresholds.
  1 As explained in other sections of this preamble,
11 compounds are also proposed for inclusion in the
Toxicity Characteristic based on their solvent
properties.
   TABLE A-7.—SUMMARY OF CHRONIC TOXICITY
            ' REFERENCE LEVELS
. Contaminant
Acrylonitrile 	

Barium 	
Bis(2-chloroethyl)
ether.
Cadmium 	
Carbon disulfide..:..
Carbon
tetrachloride.
Chlordane..:. 	
Chlorobenzene.. ......
Chloroform... 	
' chromium 	 	
6-Cresol 	 : 	
m-Cresol 	 :...:...
p-Cresol 	
2,4-D 	
1,2-
Dichlorobenzene.
1,4-
. Dichlorobenzene.
1,2-Dichloroethane.
1,1-
Dichloroethytene.
2,4-Dinitrotoluene....
Endrin 	 	 	
Heptachlor.. 	
Hexachlorobenzene
Hexacntorobuta-
dlene.
Hexachioroethane 	
Isobutanol 	
Lead.. 	 :....
Landane 	
Mercury 	 „ 	
Methoxychlpr 	
Methylens chloride...:
Methyl e'thyl ketone...
Nitrobenzene 	
Pentachlorophenol ....
Phenol 	
Pyridine 	
." Selenium 	
Silver 	
1,1,1,2-
Trichloroethana.
1,1,2,2-
Trichloroethane.
1 Tetrachloraethylene ..
2,3,4,6-
Tetrachlorophenol.
Toluene... 	 	 	
Toxaphene 	 	 	 	
1,1,1-
Tetrachloroeth-
ane.
"1,1,2-
Tetraohloroeth-
ane. .
Trichloroethylene 	
2,4,5-
Trichlorophenol.
2,4,6-
Trichlorophenol.
2,4,5-TP (Silvex) 	
Vinyl chloride 	
chron
ic
toxic
ty
refer
ence
leve
(mg/
2E-3
005
1.0...
3E-4
001
4 	
0.005
2E-3.
1 	
5E-3.
,0.05..
2 	
2 	
2 	
0.1,...
3 	
0.75..
0.005
0.007
1E-3..
2E-3.,
1E-4..
2E-4....
5E-2....
0.003...
10 	
O.OS 	
0.004...
0.002...
0.1 	
0.06.....
I.02 	
0.075...
0.01 	
.05 	
,7 	
E-2....
E-2,...
.4 	
0
.005...
.2. 	
E-3....
005...
E-2.,..
01 	
001...
Basis
RSD ' "

DWS 	
RSD.. .
oyvs
RfD * 	
PMCL 	
RSD 	
RfD 	
RSD 	
DWS 	
RfD 	
RfD 	
RfD 	
DWS 	
RfD 	 	
PMCL 	
PMCL 	
PMCL......
RSD 	
DWS... 	
RSD 	
RSD 	
RSD 	
RSD 	
Rfp... 	
dws 	
DWS 	
DWS ..........
DWS 	
RSD 	
RfD....: 	
RfD...:.... 	
RfD 	
RfD .
RfD 	
DWS 	
DWS 	
RSD. 	
RSD... 	
RSD 	 	
RfD 	
RfD
DWS 	 :....
MCL 	
SD 	
MCL 	
(D 	
SD.... 	
WS 	
MCL 	
Appor-
tionmen
(per-
cent)


•• 	 -
	 *' 	

25
- 10
'40
40
40
10


1
. 25
; ' '" 25"
, 25
25
40
-25
10
Re-
sulting
- value
(mg/l)


1.0
3E-4-

1.0
0.005
2E-3
0.1
5E-3
•0:05 • '
6.7
0.7
6.7
0.1
0.3
0 75
0005
0007
1E-3
2E-3
1E-4
2E-4
5E-2
0 003
2.5
0.05
0.004
0.002
0.1
0.06
0.5
0.004
0.25
0.03
0.01
.05
.7 ."
E-2
E-2
.1
.005
.2
E-3
005
4
E-?
01
001
  ' RSD=Risk Specific Dose.
  2 DWS=National Interim Primary Drinking Water Standard
  0 PMCL=Proposed Maximum Contaminant Level.
  1 RfD=Reference Dose.
B. Ground Water Transport Equation

I. Introduction

  Under the framework presented in
this proposal, EPA will establish
regulatory levels for individual chemical
constituents contained in hazardous
wastes. These levels are expressed as

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                     Federal Register /Vol. 51. No. 114 / Friday, June 13,1986 /.Proposed Rules
                                                                       21671
 maximum acceptable concentrations for
 individual constituents in extracts of
 -wastes. The extract concentration is
 assumed to be the same as the leachate
 concentration entering the ground water
 since the scenario assumes the bottom
 of the landfill lies directly over the
 saturated zone. EPA has developed a
 quantitative ground water modeling
 procedure to evaluate potential impacts
 on ground water and to establish
 regulatory levels for individual
 constituents. The proposed regulatory
 level-setting procedure involves a back-
 calculation from a point of potential
 exposure to. a point of release from a
 hypothetical sanitary landfill.
 Specifically, the model assesses the
 long-term chemical flux or leaching of
 toxicants ta the ground water from a
 waste disposed in a Subtitle D sanitary
 landfill The beginning point of the back-
-  calculation is, a measurement point at a
  specified distance directly ,
  downgradiant from the disposal unit.
    This procedure incorporates the
, toxicity, mobility, the persistence of
  constituents, and also the long-term
  uncertainties associated with land
  disposal.
    ' The toxicity of constituents is  ,.. -
  considered by specifying a regulatory
  level at the point of mea'surement [i.e.,
  drinking water well) and back-
  calculating to the maximum acceptable
  leachate concentration that will not
  exceed the specified standard. The
  mobility of constituents is considered
  through application of the TCLP, and for
  organics, through incorporation of  •
 " sorption as  a delay mechanism. The
  inclusion of sorption in the- ground water
  transport model is important only for
  organic constituents which degrade.
     The persistence of constituents is
  incorporated into the ground water
  model for organics by considering
   hydrolysis. Metals do not degrade, so no
   degradation is assumed. Speciation of-
   metals in ground water is an important
   factor in the extent to which metals
   migrate. The Agency is studying the use
 -.  of the MINTEQ speeiation model in  ;
   order to permit calculating element
   specific dilution/attentuation factors.
   The Agency has not been able tp
   complete these studies yet, and
   therefore will continue to employ a
    standard attenuation factor of 100. Once
    development of the fate and transport
    equation approach for the elemental
    species is completed, element specific
    factors will be proposed.
      The proposed ground water model
    accounts for most of the major physical
    and chemical processes known to
    influence movement and transformation
    of chemicals in simple, homogenous and
    isotropie porous media under steady.
flow conditions.'The mechanisms
Considered include advection,
hydrodynamic dispersion in the
longitudinal, lateral, and vertical
dimensions, adsorption, and chemical
degradation. Mechanisms not ,
considered in the model include
biodegradation, effects of sinks and
sources, and dilution of constituents
within drinking water wells.

2. Model Assumptions
  The analytical solution described
below is based on a number of key
assumptions pertaining'to the features of
ground water flow and the properties of
the porous medium. These assumptions
include the following:
   a. Saturated soil conditions (no
-attenuation of chemicals in the ,
unsaturated zone).
   b. Flow regions  of infinite extent in
 the longitudinal direction, semi-infinite
 extent in the lateral direction.
   c. All aquifer properties are
 homogeneous, isotropio and of constant
 thickness.
   d. Groundwater flow is uniform and
 continuous in direction and velocity.
   e. First-order decay is limited to
 hydrolysis and the byproducts of
- hydrolysis" are assumed to be non-
 hazardous.
   f. Sorption behaves linearly.
   g. Infinite source—supplies a constant
 mass flux rate.
   h. Ground water recharge is
 accounted for.
   i. The ground water is initially free of
 contamination.
   j. The receptor  well is directly in line
 with the source and the ground water
 flow.'      '•'..-'•'                 •   ;
   The effect of the first assumption is to
  presume that a waste is placed directly
  at the top of the saturated zone. Since
  EPA has found that a significant number
  of hazardous waste landfills are located
  within a-few feet of an aquifer, and
  since Subtitle D facilities are generally
  sited £n similar environments, this
  assumptionis believed to be reasonable.
  This worst-case assumption predicts
  that no attenuation occurs during the
  migration of constituents in leachates to
  the underlying aquifer.  .
    The second assumption of infinite.and'
  semi-infinite flow regions in the
  longitudinal and lateral direction,
  respectively, is appropriate for all
  simplified analytical ground water flow
  models. (The term semi-infinite refers to
  the fact that once a leachate reaches an
  aquifer, although theoretically it can
  disperse in the lateral direction to an
  infinite degree; for all practical purposes
   there is a point at which further
   dispersion has little effect on the
   concentration of contaminants within a
plume. Although further dispersion
would still be greater than zero, its
effect is insignificant.) Aquifers have
finite areal extent, however,-and may be
confined by'impermeabfe layers. If an
aquifer is confined by an impermeable
layer in the [longitudinal or lateral fields,
this assumption will underestimate.
downgradient concentrations.
  The assumption of homogeneous and
isotropie aquifer properties is rarely
encountered in the field, but the
availability of data and the generic
nature of this  analysis requires the use
of a homogeneous and isotropie
approximation. Also, this  assumption is
usually^ employed if the solution of the
problem is obtained by analytical
techniques, "                           •
   A uniform flow velocity, the fourth
 assumption,, presumes that the water
 volume entering from the  source is" not
 large enough  to affect the natural ground
 water gradient. This assumption is
 appropriate for simplified analytical
 solutions, la situations where the ground
 water flow! system contains sinks or
 sources (e.g., pumping or injection
 wells), drastic changes in the velocity
 distribution will occur. Under this
 situation that steady-state down •
 gradient contaminant concentrations  •
 may be underestimated.
    Hydrolysis of first-order kinetics, the
 fifth assumption, is the only mechanism
 for transformation considered in the
 proposed model. While other
 transformation mechanisms-, such as
 biodegradation and oxidation are also,
 important;, the Agency's present
 understanding of these mechanisms
 does; not yet permit a kinetic    —/
 representation: of these processes within
 the. system modeled. The effects,
 relative importance,  and interactions of
 these processes in the ground water
  environment are not well understood
  and are under investigation.
    In general, all^transformations are
  dependent upon both the: chemical
  constituent and the prevailing
  environmental properties.: For
  hydrolysi s, ground water pH and
  temperature must be known. The
  Agency's analysis to date has identified
  more than 20,000; measurements for pH
  and temperature frorn which distribution
  functions! can be assigned for purposes
  of evaluating variation and uncertainty.
  Similar .data describing microbial
  populations, metabolizable carbon
  sources; etc.,.,are.not generally available.
  The Agency tfeiieves that given this
  limited understanding of the factors
  influencing  biodegradation and.
   oxidation in the ground water
   environment,, prudence  dictates that
  • these processes not be included in the

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  21672
                                         V°L 51' No' 114 I Friday- June 13'1986 /Proposed Rules
  model. By including only hydrolysis in
  the model, the Agency is being
  conservative.
   The seventh assumption of an infinite
  source represents a worst case. To
  ensure that waste disposal is protective
  of human health and the environment in
  all possible situations (which do not
  address the total amount of waste
  disposed), the Agency believes it is
  prudent to adopt this conservative   -
  assumption.
   The assumption of dilution of the
  contaminant plume  by ground water
  recharge accounts for a process known
  to occur in the environment. Ground
  water recharge leads to further dilution
  of the contaminant plume as it moves
  downgradient from the facility. EPA
 recognizes that it is  difficult to develop
 precise estimates of ground water
 recharge for incorporation into a generic
 mode. Data is available, however, from
 xvhich rough estimates can be
 developed.
   The assumption of placement of a
 well in the exact position to receive the
 highest concentration of a contaminant
 represents an absolute worst case. The
 Agency believes  this assumption is
 appropriate for use in the model since it  -
 is possible that some drinking water
 wells are directly in  line with Subtitle D
 land disposal  units.
 3. Cumulative Frequency Distribution
   Through use of a Monte Carlo
 computer simulation, the ground water
 transport equation results in a
 cumulative frequency distribution. The
 cumulative frequency distribution
 provides estimates of the likelihood or
 probability that the target concentration
 level (e.g., reference dose), would not be
 exceeded, given the range and
 distribution of the values that may be
 expected for each of  the various
 environmental parameters known to
 affect such concentrations. For the
 purposes of this regulation, EPA is
 proposing to use the 85th  cumulative
 percentile. EPA believes that using the'
 85th percentile will provide a reasonable
balance between the  need to identify the
majority of truly hazardous waste as
hazardous, while at the same time
  minimizing the false identification of   ,
  non-hazardous waste as hazardous.
  Note, however, that EPA is considering
  the use of both the 80th and the 90th
  percentile for this regulation. For non-
  degrading compounds, the 80th and 90th
  percentiles produce dilution/attenuation
  factors of 22 and 10, respectively;
   The regulatory levels being proposed
  today are based on the 85th cumulative
  frequency percentile. As indicated
  previously, this does not necessarily
  mean that EPA is unconcerned about
  wastes which may exceed levels based
  on some higher percentile (e.g., 90
  percent).. Specific wastes whieh the
  Agency finds not to be hazardous using
  the regulatory levels based on the 85th
 percentile, but which could exceed
  thresholds based on some higher
 percentile, and which are determined to
 pose a hazard to ground water, may be
 specifically listed by the Agency as
 hazardous wastes under §§ 261.31 or
 261.32.         ^               .

 4. Further Information

   The Agency has proposed to use the
 same basic ground water transport
 equation and health effects thresholds
 for use in the Land Disposal Restrictions
 Rule (51 FR 1603), proposed on January
 14,1986. Differences in the equations
 have been introduced for the proposed
 Land Disposal Restrictions Rule, to
 account for the additional engineering
 controls required (e.g., landfill caps),
 when managing wastes as hazardous in
 a Subtitle C hazardous waste facility,
 and the higher standards of confidence
 required under the HSWA for
 determining that a waste is suitable for
 land disposal.
  While this proposal outlines the
 equation's proposed use in the Toxicity
 Characteristic, considerably more detail
 concerning this equation is provided in
 the preamble section to the proposed
 Land Disposal Restrictions Rule. The
 reader is referred to that preamble, and
 the reference noted therein, for further
information on the equation and the
 data used in running it. The computer
printouts obtained as a result of running
 the equation on .the compounds will be
included in the Toxicity Characteristic
docket. _,

C. Tables of Proposed Contaminants
'and Data Used to Develop Regulatory
Levels

   TABLE C-1.—TOXICITY CHARACTERISTIC
        CONTAMINANTS AND LEVELS
HWNO'and contaminant
D018— Aorylonitrile 	 ,
D004— Arsenic 	 ; 	
0005 — Barium .
D019— Benzene 	 :
D020— Bis(2-chloroethyl)ether 	 	
D006— Cadmium 	
D021— Carbon disulfide 	
D022— Carbon "tetrachloride 	 	
D023— Chlordane 	
D024— Chlorobenzene 	 :....
D025— Chloroform 	 	
0007— Chromium 	 . ,
D026— o-Cresol 	
D027— m-Cresol 	 '.. 	
D028— p-Cresol 	 .'...
D016— 2,4-D..; 	
D029— 1,2-Dichlorobenzene 	
0030— 1,4-Dichlorobenzene 	
D031— 1,2-Dichloroeihane 	
D032— 1,1-Oichloroethylene 	
D033— 2,4-Dinitrotoluane 	
D012— Endrin 	 	
D034— Heptachlor (and hydroxide) .....
D035 — Hexachlorobenzene....
0036— Hexachlorobutadiene.; 	
D037— Hexachloroethane 	 s
D038— Isobutanol; 	
D008— Lead 	 • , , ,,
D013— Lindane 	
D009— Mercury 	 	 	 ,
D014— Methoxychlor 	 	
D039— Methylene chloride 	
D040— Methyl ethyl ketone 	
D041— Nitrobenzene 	
0042— Pentachlorophenol 	
D043— Phenol 	 	 	
D044— Ryridine 	 	
D010— Selenium 	
001 1— Silver 	 	 	
D04S— 1,1,1,2-Tetrachloroethane 	 	
0046— 1,1, 2,2-Tetrachloroethane 	
0047— Tetrachloroethylene 	
D048— 2,3,4,6-Tetrachlorophenol 	
0049— Toluene 	 	 	
D015— Toxaphene 	
DOSO— 1,1,1,-Trichloroethane... .
0051— 1,1,2-Trichloroethane. . .
0052— Trichloroethytene.... 	 	 	 -
0053— 2,4,5-Trichlorophenol 	
D054— 2,4,6-Trichlorophenol 	 	 	
0017— 2,4,5-TP (Silvex) 	 '
0055— Vinyl chloride 	

Casno2
107-13-
7440-38-


111-44-4
75-1 5-
56-23-5
108-90-7


95-48-7



95-50-1
1 06-46-7

75-35-4

- 72-20-8
76-44-8
118 74-1
87-68-3

7439-92-1
58-89-9

72-43-5
75-09-2


87-86-5


7782-49-2

630-20-6
79-34-5
127-18-4
58-90-2
108-88-3
001-35-2
71-55-6

79-01-6
95-95-4
88-06-2
93-76-5


Regula-
tory level
(mg/1)
50



, 0.05

0.07













0.001
0.72













10.0
1-3 .
,1-5









1 Hazardous Waste Identification Number.
2 Chemical Abstracts Registry Number.
                    TABLE C-2.-METHODS AND QUANTITATION LIMITS FOR TOXICITY CHARACTERISTIC CONTAMINANTS
Contaminant
AcrytoniWo, 	 „ 	 	 L ^ _


BJSfzSSoT "ttT'i ihfflr — ™" 	 	 "'


Cutoofl totrachlofkte 	 „.. 	 '
Chkxdtna 	 	 „ — 	 ,
*
Vol.'
V


V


V


SW-846 methods 2
503D/8240. _ " "
7060, 7061 	 	 	
6010, 7080. 7081
5030/8240 	 .. , 	
3510/8270 	
6010,7130,7131 	 , , 	
5030/8240 	 : 	 . .„„ 	
8080 	 •

Detection
limit (mg/






1.0
0.01 .

Quantitation
limit (mg/
1)4






5.0
0,05


-------
Federal Register / Vol  51. No. 114 /_Friday. .June'13.1988 / Proposed Rules
21673
TABLE C-2 -METHODS AND QUANTITATION LIMITS FOR TOXICITY CHARACTERISTIC OONTAM.NAN ,,,-ou, ,u, ,u
Contaminant

Chlorobenzene _ _
Chloroform 	 - - -v—
Chromium - - ~
o-Cresol. ~ -
M-Cresol ,
P-CresoE. —
2,4-D. -
1,2-Dichlorobenzene, - -
1 ,4-Dichlorobenzene
1,2-Dichloroethane. _ _
i,1-Dichloroethylene. ~
2,4-Dinitrotoluene 	
Endrin._ 	 - -
Heptachlor (and its hydroxide) , -
Hexachtorobenzene — __- - -
Hexachtorobutadiene -_ 	
HexachToroethane 	
Isobutanol . , — 	 --— - 	 	
Lead, - '
Lindane *
Mercury,
Methoxychlor. '
Methylene chloride i
Methyl ethyl ketone , i
Nitrobenzene
Pentachlorophenol i
Phenol.
Pyridine.
Selenium.
Silver.
1.i.1.;2-Tetrachloroethane .
1.1-.2.2-Tetrachloroethane, — - t
Tetrachloroethylene 	
2.3.4,6-Tetrachlorophenol.
Toluene - '
Toxaphene, \ - — 	 „-
f,1.1-Trichloroethane — 	 —
t.1.2-Trichloroethane. 	 	 — - - ~
Trichloroethylene - 	 	 	 ~ 	
2,4,5-Trichlorophenol , -
2,4,6-Trichlorophenol , - — 	
2,4-,5-TP (Silvex) 	 	
Vol.'
V
V







V
V


V



V
V




:. \







SW-846 methods 2
030/8240. r , "
030/8240. _
010, 7190, 7T91
510/8270
510/8270 ,.
510/8270.
150 	
510/8270
510/8270.
030/8240.
030/8240.
51078270..
080 	 -
080 	
3510/8270
3510/8270.
3510/8*270. - .t ,
503078240.
6010, 7420, 7421
8080.- 	
7470, 7471
8080 ......
5030/8240. ,
5030/8240.
3510/8*270.,
3510/8270.
,3510/8270.
3510/8270. - ...... 	
6010. 7740. 7741
6010, 7760, 7761
5030/8240.
5030/8240.
5030/8240.
3510/8270., ,
5030/8240 - 1
8080 	
5030/8240.
5030/8240.
5030/8240.
3510/827a__
3510/8270.
8150... ,
5030/8240.- - - -
GV4
Detection
imit (mg/
D3
0.01
0:01
0:02
0:10

0.10
0.005
0-.025

0.025
0;01
O.OT
0.025
0-.0001
0.0001
0.025
0.025
0.025
T..O'
0:08
0.0001
0.0004
0.0005
0,025,
0.01,
0.025
n m
U.Ul
0.025
1 0
0 01
t\ m "
U.U I.
0 01
0.01
0.01
0.10-
•6.01
.0.005
0 01

O.OT

0.05
0.05
O.OOE
0.01

uantitation
imit (mg/
1)<
0.05
0 05
OiTO
0:50
0-.50
0.50
0.025
0.125
0 "125
0.05
0 05
0.125
0.0005
0.0005
0.125
0.125
5 0
O4O
0.0005
0.002
- 0.0025
0.125 .
0 05
0.125
0-.05
0.125
5.0
0.05
0.05
0.05
0.05
0.05
0:50
0.05
0.025
0.05
0 05

0.25
0.25
' 005

^sr^ En— ntal pfote*n Aflenoy' '** 1982 ^*fo^he"oitocomp™nds

TABLE C-3 -CHRONIC TOXICITV REFERENCE LEVELS FOR TOXICITV CHARACTERISTIC CONTAMINANTS
Contaminant

Acrylonitrile — -

Barium 	 ' — — ^ "
Benzene 	 -- — ' "
Bis(2-chloroethy.l)ether 	 	
Cadmium —
Carbon disulfide. - — ~ ~
Carbon tettachloride. _ .
Chlordane. - —
Chlorobenzene 	 _ -- - —
Chloroform . - - "
Chromium. - 	 "
o-Cresbl .... . — *™
m-Cresol .- -• ~

p-Cresol — -- - - -
2,4-D 	 -
1,2-Dichlorobenzene,
1,4-Dichlorobenzene. . 	
1 ,2-Dichloroethane ~ "
1 ,t-Dichloroethy!ene.
2,4-Dinitrotoluene. — -
Endrin ...,._
Heptachlor (and hydroxide). 	
Hexachlorobenzene - 	
Hexachtorobutadiene
Hexachlo'roethane -
Isobutanol - ' » "
Lead 	
Lindane ...
Mercury... < — - -
Methoxychlor. -
Methylene chloride.
Methyl ethyl ketone.
Chronic- toxicity reference- leyet (trig/I)11
002(RSD>. - -
05(DWS)..
0(DWSJ. -- -
0005(PMCL).
0.0003(RSD),
0.01 PWSJ..
4(RfDJ...
0.005(PMCtJ..
0.002(RSDJ,
I (Rf D) ..
O.OOS(RSD),
0.05(DWS).. - •
2(RfD). 	
2(RfD)..
2(RfD) ..
0.1(DWS).
3(RfD) ..
0.75(PMCL).
0.005(PMCL). - ^
0 001(RSD)
0.0002(DWS). - -
O.OOOT(RSD).
0.0002(RSD).
0.05(HSD) ,
O.S(RSD)
10(RfD(.
0.05(DWS).
0.004(DWS)
0.002PWS) ,
0.10(OWS).
0.6(RSD)
2(RfD)
0.02(RfD).
LOG Kow2
„

^
-
2:18
2;87

2.15
2.15
2.15

3.56



0.74


03
1.9
lh(atra m.3/mol^3

' *


'.68E-2
S.46E-3

5.05E-S
5.05E-&
iS.OSE-6

1.88E-3,



1 23E-5-


2.61 E-5
Z.40E-5

Apportion-
ment
(percent)4




25
to

40~
40
40

ia



25


2
2

Apportioned
reference
level (mg/l)a
0.002 .
O.OS
T.O
0.005
0:0003
0.01
1,0
0.005
0.002
0:1
0.005
0:05 '
0:7
0.7
0.7
O.1
0\3
0.75
0.005
0.007
0 001
0000!
0.0001
0.0002
0.05
0.3
2.5
0.05
0:604
0.002
0.1
b.&
0.5
0 004


-------
21674
Federal Register / Vol. 51, No. 114 / Friday, June 13,1986 / Proposed Rules
                 TABLE C-3.—CHRONIC TOXICITY REFERENCE LEVELS FOR TOXICITY CHARACTERISTIC CONTAMINANTS—Continued
: Contaminant
PentacMofoprwmol.. 	 „..„,..._ 	 	 _ 	
PyfNflno "~ """ 	 """ "" 	 " 	 *
Setanum..., 	 „ .„„„.„„..,..„.„
Sdvw, ' 	 ' 	
1,1,l,2'Tctrn:MotcK!lluno ...„,.„ 	 „..,...„.. „. i
1,1 AZ-TeKacfikKOdlhana „.„...„ 	 „ 	
To«fad*xoolty!ene 	 . 	 „. „, 	 „,. .
2A<6-T«tr«cl*xopband...,. 	 	 „
Tofcw 	 	 	 	 	 	 	
Chronic toxicity reference level (mg/l)1
1(RfD)
4(R(D) 	 „.. - .
0.075(RfD) 	
001(DWS)
0 OS(DWS)
0.7(RSD) 	 ',.. .
0.02(RSD) 	
0 007(RSD)
0 4(RfD)
10(HfD) 	
O.OOS(DWS) 	
0,2(PMCL) 	 '
0.06(RSD) 	
O.OOS(PMCL) 	
4(RfD) 	 ,.,., 	
0 02(RSD)
001(DWS)
O.OOI(PMCL) 	
LOG Kow «

1.49
0.68









.
. 3.86


Khfatm m''/mol);1

4.5E-6
1.95E-7










2.84E-S


Apportion- /
men! \
(percent)4

40
40







" 	 ' 	

" .
10


Apportioned
reference
level (mg/l)=

1.0
" , .APS;. .





, ..Q.j1 , •-



, 0.005
'.'0.4

0.00U1
   1 OWS- National Interim Primary Drinking Standard.
   JJMCL=Proposed Maximum Contaminant Level (Proposed standard in drinking water).
   RfO«ne!echlotoprKmol .,„ 	 	 	
Toh»n»«..,,B.,.,™™..,..M..... 	 ,.„.. 	 	 	
Tonaphana. — ,.™ 	 .,„ 	 	
1,1,1 -TncNof o«than«.™...,,™,M«m........™ 	 „ 	
l.l-Z-Tnehkxoethane.,.. 	 	 	 „..„ 	
2,4,8-TrtchtofOplianol." ZZZZZZ "
2,4,5-TP (Siivoic) 	 . 	
Vinyl chfofKlo «.»™.™.w..,™«n,,..MM.« """'
1 LOO Oclanol Walcsf Partition Coefficient

LOG Kow'
0.07

2.13
1.04
2.16
„ 2.96
'5.48
2.87


• 2 15
2.70
3.56
1.40
2.13
2.30
"4.61
6.42
4.22
0.74
3.40

1.26
0.3
1.90
506



2.81
2.42
3.03
4.33
2.82
'5.30
2,50
2.28
3.86
3.45
1.38


Ka *
>1/Y,.

NHYF1.
NH5.
NH
NH.
NH.
NH.



NHYF.
NH.
NH.
NLFG.
NuFG.
NLFG.
NLFG.

NH.
NLFG.
NLFG.
NH



NH.
NH.
NLFG.
NH.
NHYF.
NH.
NH
NLFG.
NH.
NH
NLFG.
NH,
5 NH = Negligible Hydrolv
Hydrolysis rate constants
Kb"*,
>1/Yr.
1
NHYF.
NH.
>10/Yr,
NH.
>10/Yr.,
1E-6/Hr.



NHYF.,
1E-5/Hr.
NH.
NLFG.
NLFG.
NLFG.
NLFG.'

NH.
NLFG t.
NLFG.



1.3/Hr.
2.6E+3/Hr.,
NLFG.
1E-5/Hr.
NHYF.
>10/Yr.
NH.
NLFG.
1E-5/Hr.
NLFG.
1E-5/Hr..f
3is.

Kn2
>1/Yr.. ,"
'
NHYF.,
8E-5/Hr.
NH.
NH.
NH.
NH.


NHYF.
NHYF.
NH.
7.2E-5/Hr..
NLFG,
NLFG,
> 1 /Yr.
NLFG.
NLFG. ,
IV
1.18E-8/Hr.
NLFG.
NLFG.


NLFG.
2.2E-7/Hr.,
NH.
NLFG,
NH.
NHYF.
NH.
1.1E-4/HK.
NLFG.
NH.
NLFG,.
1E-7/Hr.


D/A
• factor?
144
100.0
100.0
14.4
144
14.4
14.4
14.4
14.4
14.4
100,0
14.4
14.4
14.4
1,4.4
14.4
14.4
-75,'0
14.4
14.4
14.4
14.4
;14.4
,14.4
14.4
14.4
too.o
14.4
100.0
14.4
14.4
14.4
14.4

,14.4,
, 14.4
> 100.0
100.0
14.4
65.0
14.4
14.4
14.4
14.4 "
150.0
20.0
14.4
14.4
14.4
14.4
14.4

  j        .                       round water transport equation.
  * NHYF a No Hydroryzabte Functional Group.
                                                             ' Estimated value.

-------
                  Federal Register / Vol. 51, No. 114 / Friday. June 13. 1986 / Proposed Rules
                                                                                             21675
                         TABLE C-5.—•REGULATORY LEVELS FOR TOXICITY CHARACTERISTIC CONTAMINANTS ; •


Contaminant:
Acrylbnitrile J
Arsenic
' Barium,
. Benzene.
Bis(2-chloroethyl)ether ,
Cadmium. ~
Carbon disulfide;
Carbon tetrachloride.
Chlordane
Chlordberizene
Chloroform.
Chromium.
o-Cresol. *
m-Cresol.
p-Cresol. *
2,4-D
1.2-Dichlprobenzene ,
1,4-Dichlorobenzene. _ v
1 ,2-Dictiloroethane- ' " ' ,
1,1-Dicnloroethylene. , - "
2,4-Dinitrotoluene.
Endrin t
Heptachlor (and hydroxide) .
Hexachlorobenzene..;v. >
Hexachtorobutadiene. ..
Hexachioraethane. * ^
Isobutanol. v
" Lead.
Lindane <
Mercury
Me.thoxychlor. - «
Methylene chloride , . »
Methyl ethyl ketone
Nitrobenzene '
Pentachlorophenot .
Phenol
Pyridine
Selenium .
Silver, . •
1,1,1.2-T.etrachforoethane. - f
1 ,1 ,2.2-Tetrachloroethane.
Tetrachloroethylene.
2.3,4,6-Tetrachlorophenot,
toluene
Toxaphene. ,
• 1,1.1-Trichloroethane
1,1,2-Trtchloroethane ,
, Trichloroethylene
2,4,5-Trichlorophenol. i -
2.4,6-Trichlorophenol. ,
2,4.5-TP (Silvex).
Vinyt chloride.
Apportioned
chronic
toxicity
reference
level (mg/
D1
0.002
0.05
1.0
0.005
0.0003
0.01
1 0
0.005
0.002
0.1
0.005
0.05
0.7
0.7
0.7
0.1
0.3 •
0.75
0.005
0.007
0.001
0.0002
0.0001
0,0002
0.05
0.3
2.5
0.05
0.004
0.002
0;1
0.6
0.5
0.004
0.25
1."0 •
0.03
.0.01
0.05
0.7
0 02
0007
0 10
-1.0
0.005
0.2
0 06
0.005
0.4 "
0.02
0.01
0.001


D/A .
factor =
14.4
.100.0
100.0
'14.4
14.4
100.6
14.4
14.4
14.4
14.4
14.4
100.0
14.4
14.4
, 14.4
14.4
14,4
14.4
75.0
14.4
" 14.4
14.4
14.4
,; ''14.4
''14.4
14.4
' 14.4
100.0
14.4
. 100.0
14.4
1 14.4
' .14.4
, 14.4
1 4.4
14.'
14.4
100.0
'•' 100.0
' 14.'
65,(
14.'
14,'
14>
14.'
150
20.
• 14.'
14.'
14.'
14.'
''- 14.


t-f'-': ' '••'
Calculated
evel (mg/
i- D" ,
: - 0.029
; 5.0
''lob
6.072-
[' 0.004 .
.... 1S,.,,
1 14.4
I . 0.072
i 0:029 .
; * 1.44'
J - 0.072
:'"• 5.0
: 10.08
; 10.08
r 10.08
i. 1.44-
,' ,4.32
10.B
0.40
0.1008,
• . 0.0144 ,
L 0.0029
™ 0.0014
-; 0.0029
', , 0.72'.
': :4.32'
' 36
5.0.
1 0.0576
0.2
••••' " 1.44 -
'; ' '8.64'
-, - 7".2
.J " . 0.0576
J1.' - 3.6
1 ; 14.4
;.v 6.432
i; •' 1.0 •:
V 5.0
; '10.08
•','• . .1.3
;['' ' 0.100
•V.44
•;;, ,.14.4.;
. 0.072
t'' 30-' '
" .- ' -1.2 •
!• 0.072
II ' 5.76
I 0.288
0.144
: ' • 0.014

— — 	 	 ! - '• : ^ "
.
Quantitation
mit(mg/1)4
,5.0
0.025
6.05
0.05
'0:05
0.05
' 5.0
0.05'
0.0025
0.05
0.05
6.1' •
. 0.5
. ':0.5
'0.5
0.025
,0.125
6.125
0.05
0.05
0.125
0.0005
• ' 0:0005
0.125
0.125
'6.125
5.0
.0.4
0:0005
0.002
0.0025
0.125
• .0.05
... 0.125
0.05
0.125
:5.0.. ",
. 6.05. '
0.05'
• 0.05 '
0.05
0.05
-0.5 ,,
0.0.5
0.025
. 0:05
0.05
. 0.05,
0.25
0.25
0.025
0.05

Regulatory
level (mg/
, . (5.0)
5.0
100
' 0.07 •
. (0.05)
1.0
14^4 ".
. 0.07
'0.03
. , U4
- '0.07
5,0
' '10.0
• 10.0! -.. .
10.0
' 1.4
4.3
10.8
0.40 '
,0.1
(0,13)
0.003
v 0.001
, (0.13)
0.72 \
4.3
. 36 -
5.0'
0.06
-;.,-:0:2 .
1.4
a:6
:7.26
(0.13)
3.6
• 14!4
- (5.0)
\ 1.0
5.0
'10:0
' , 1.3'
':• 0.1
1 1.5
14.4 -
0.07
, 30 -
1.2
0.07
5.8 •
• 0.3'
. '0.14
(0.05)

s — ... 	 	 	 =— ~ ^ • ' .' "" .-.'..• . .-',-? '-..,.
   'See Table C-3.
   3 Apportipned Chronic Toxicity Reference Level multiplied by Dilution/Attenuation Factor.

  "
is greater than the calculated level, the Quantitation limit becomes the (technology based) regulatory level (indicated by fevei^pa
               limit i
D. Development and Evaluation of the .
TCLP    :       ' •• .-    '        .-;.••
i. Introduction        .' -'    ';.-.,

   This Section provides detailed  ...'.'
information oh how the TCLP was ."  .  ,
.developed and evaluated..Still more  , .
detailed information regarding the TGLP
is available in-.a Background Document
that EPA has prepared for the TCLP   ;
(Ref. 33).
2. ExperimentalDesign

   EPA, through an interagency
 agreement with the U.S. Department of
                       Energy's Oak Ridge National Laboratory
                       (ORNL), has conducted a research
                       program designed to develop ah
                       improved leaching test, the TCLP. The
                       TCLP development program was split up,
                       into three phases. Phases. I and II, and
                       part of phase III have been completed.
                       Phase I consisted of an initial data
                       gathering effort in which a number of
                       wastes were leached with a teachate
                       derived fr.om municipal refuse. The
                       wastes were, also extracted with a
                       variety of laboratory leaching media
                       and contact procedures. Phase I was
                       designed to narrow the universe of
potential candidate leaching procedures.
In Phase II,-additiohal wastes were
leached and the candidate procedures
refined into the .draft TCLP. During this
phase of testing, public assistance and
review of the draft was solicited.  '  ;  '
  The  overall apprbach'employed in  • ;
Phase I was as follows:   •     .
  a. Large-scale field lysimeters were
filled with  domestic and commercial
refuse and useid to generate a municipal
waste leachate (MWL).
  b. The MWL was used to leach four
industrial solid wastes in large columns.

-------
   21676
                               •ejht,_./nV°L 51' No" 114/ ^ridav. June 13,1986 / Proposed'Rules
     c. The leachate concentration of a
.  number of organic and inorganic species
   that were present in each waste were
   measured over time.
     d. A total of 34 laboratory leaching
   tests were run on the four wastes to
   assess their accuracy in modeling the
   results of the lysimeter/column
   experiments. These tests included both
   column and batch procedures using four
   leaching media (i.e, sodium acetate
   buffer, carbonic acid, water, and  actual
   municipal waste leachate), and four
  media to w,aste ratios (i.e., 2.5, 5,10, and
  20 to 1). In addition, the EP and a
  sequential batch leaching procedure
  were also investigated.
    e. Target Concentrations (TCs), were
  established for each constituent based
  on the lysimeter/column leaching
  curves, by calculating the amount of
  constituent leached over a specific
  leaching interval (i.e., an amount of
  leachale equal to twenty times the
  weight of the original industrial solid
  waste—twenty to one liquid to solid
  ratio).
    f. Laboratory leaching test results
  were compared to the TCs,  and the two
  laboratory tests that best replicated
  lysimeter results were selected for
  further evaluation in Phase  E.
    Phase II of the program involved
  extensive evaluation and verification of
  Phase I:
    a. Seven wastes were leached in
  essentially the same experimental
  arrangement as used in Phase I.
   b. Each waste was subjected to the  "
  two "best" leaching procedures selected
  from Phase I, as well as the EP.
   c. The single procedure which best
 satisfied the objectives presented in the
 body of this preamble was selected as
 the draft TCLP.
   d. the draft TCLP was then circulated
 to interested members of industry,
 academia, environmental groups, and
 other with interest and experience
 conducting such tests, for comment.
   Phase III of the program involved
 subjecting the draft TCLP to an
 evaluation of ruggedness and precision.
 This work has been partially completed
 and the design and results to date are
 summarized further in this Section.  ~"
Another part of Phase III which is
currently ongoing is a multi-laboratory
collaborative evaluation of the draft
TCLP. (The TCLP has evolved to its
present form in response to both Agency
activities as well as to comments
received on the circulated drafts.) The
following sections present the
experimental program and the results.
3. Results of Phase I
  The ORNL Phase I report explains in
detail the experimental approach and
   describes the results, obtained during the
   first phase of testing (Ref. 6). Briefly,
   lysimeter leachate target concentrations
   were established based on both
   practical considerations and the need to
   represent a mid-to-long term leaching
   interval or exposure period. This was
   important as the purpose of the leaching
   test is .primarily to  evaluate the
   migratory potential of chronically toxic
   organic compounds (Ref. 17). (Use 'of
   chronic toxicity values  are discussed in
  more detail elsewhere in this preamble.)
    The various laboratory procedures
  tested were then compared as to their
  ability to reproduce the lysimeter
  leachate target concentrations. The
  absolute value of the percentage
  difference for each  target concentration/
  leaching test concentration pair was
  determined, averaged for each leaching
  procedure, and then each procedure was
  ranked from the lowest  to highest
  difference and evaluated for
  significance using Duncan's multiple
  range test. These analyses identified
  most of the laboratory procedures as  ^
  being equally predictive of lysimeter
  leachate target concentrations,
  particularly where the organics were
  concerned.
   No single procedure will be able to
  accurately predict leachate
  concentrations for all compounds in all
  waste matrices. EPA therefore picked
  the procedures which seemed to most
  closely model lysimeter leachate target
  concentrations using the absolute value
 of the percentage difference. Factors
 other than average percentage
 difference, such as ease and expense of
 operation, applicability to both organics
 and inorganics, and-applicability to
 biological testing, were also taken into
 account. These factors were identified in
 the body of the preamble as objectives
 for the TCLP.
   On the basis of all these
 considerations, two procedures, similar
 in concept and operation to the current
 EP, were selected for further work in   '
 Phase II. Both of these procedures use a
 20:1 liquid to solid ratio (i.e., an amount '
 of extraction fluid equal to twenty times
 the weigth of the solid phase of the
 waste) and involve a batch-type
 extraction. One procedure uses a 0.1 N
 pH 5 sodium acetate  buffer solution-as
 the extraction medium, and the other
 uses carbon dioxide (CO2) saturated
 deionized. distilled water  (i.e., carbonfc
 acid).

 4i Peer Reviews

  A number of peer reviews were
 conducted at various stages of the TCLP
development program. The general tone
of these reviews was always strongly
positive. One such review which
  deserves attention, primarily because it
  had profound effect on the way the
  TCLP development data was analyzed,
  is a'review conducted by the Agency's
  Science Advisory Board (Ref.;2§).
    At the end of Phase I/the  -
  Environmental Engineering Committee
  of the Science Advisory Board (SAB)
  was asked by EPA to review and
  provide recommendations concerning
  the  development program and the
  selected methods. Overall, the SAB
  found that the experimental approach
  taken reasonably represented an actual
  landfill. The SAB did, however, question
  the  statistical methodology used to
  evaluate the Phase I data and
  recommended that the data be re-
  evaluated  using additional statistical
  analyses. Their primary concerns were
  the need to provide more resolution in
  the data through the  use of more
  powerful statistical tests, the need to
  indicate the direction of the statistical
  differences (i.e., were individual
  laboratory tests generally more or less
  aggressive than lysimeter targets) and
  the need to examine  the data for
  possible compound or class-related
  trends.         ,             '' . • •

  5. Results of Phase II    "'           -

   The SAB comments resulted in the
  application of a number of additional
  statistical tests to both  the Phase I and
  Phase II data, and the Phases I and H
  combined data (Ref. 7 and 25). Before
  describing the results of these statistical
  analyses, it is important to bear in mind
  that no single leaching procedure will be
 able  to accurately predict leachate
 concentrations for all compounds in all
 waste matrices. The idea was to select
 the procedure which most consistently
 modeled the field lysimeters. Another
 consideration was the need to minimize
 the occurrence of false negative results
 (i.e., the situation where the leaching
 test falsely identifies the waste as non-
 hazardous in this case the leaching test
 would be less aggressive than field
 results). While it is important to also
 minimize the occurrence of false
 positives, EPA believes that minimizing
 false  negatives is more important, since
 the consequences of false negative
 results are more environmentally
 serious. In addition, other factors, such
 as ease and expense of operation,
 applicability to both organics and
 inorganics, reproducibility, and
 applicability to biological testing (the
 original objectives in developing the
TCLP), were also considered in selecting
 the  most appropriate leaching medium.
  Table .D-l .summarizes the results of
four of the more important statistical
analyses applied to the data comparing

-------
                    Federal Register /Vol. 51, No. 114 / Ffiday,;June 13, '19'86 / Proposed fRiiles
                                                                                                               :21677
lysimeter, to.laboratory results. This
table presents comparisons between
three extraction media (i.e., acetate    ,
buffer, carbonic acid and EP leaching
medium), and includes the results for
both organics and inorganics from both
phases of testing. Only statistically
significant results are presented. A
                                        different letter indicates statistical
                                        significance at the 5 percent level, an
                                        "A" value being closest to the lysimeter
                                        results, .The results reported in this table
                                        come from several references (Ref. 6, 7,
                                        and 25): Also, see the TCLP Background
                                        Document (Ref. 33).  .;  '-
  TABLE D-1.—SUMMARY TABLE—STATISTICAL ANALYSIS OF THE DATA' USED To DEVELOP THE
      TOXICITY CHARACTERISTIC LEACHING PROCEDURE STATISTICAL SIGNIFICANCE ONLY ?.

Absolute percent D *: •

EP ,. 	 	 ,...; 	 	 	 ....
Actual percent D a; •


Multivariate •*:
Acetate 	 	 	 	 	 ....
Carbonic 	 	 	 	 	 ......
Precision (C.V.) *: •••.-'

EP 	 ...'....v 	

Inorganic's
Phase. '
- 1
CO < CD . CD < CO'
"•/=.. ;•• <:''«

A
A
. ND
Phase
' 'II
•. A-
A
• A
-; -AS


' A
B
B
P"hase
. I + M
A
.A
A
. ; -B
• + A

A
B
'• ' ,B
\ .Organics'.'
Phase
1
• .' "A
. ,*.
A
' + A
+ A

'• D
• B
• ND
Phase
II
. A
' . A
' .; +A
.-+-A-
'S +A

• o .0 co
Phase.
If".
A
, A
" •. 'A'
+A
+AB
+ B

B'
.-.' . C
C
Inorganics and prganics '
Phase
• , A
, A
.-'' -A
' -A.
'. ' A
. • B
;" B
• . A
ND
Phase.
II
• <<< < co <   '  •  .'•<'••'..'.•.
   The analysis qf precision, the last"   '
 statistical analysis.presented in Table ,
 D-1,.also indicated that the acetate,
 buffer•'•extraction, would provide a more
 precise test procedure than either of the
 other two media. In addition, the acetate
 buffer system offers a number of      ..
 operational;advantages over either the,
 carbonic acid medium or the EP leaching
: medium..Finally, use of the acetate
 buffer systejn! should minimize the    ;
 occurrence bf false negative results,
 since the Wiase'if inorganics analyses
 indicated trial the .carbonic acid medium
 was less aggressive than the lysimeter _
 field results. •           "
  . For the abpv'e reasons, the sodium
 acetate buffer system has been, selected
 as the medium of choice. Perhaps the
 only objective that may have been    :
 compromisibd by  selection of the acetate
 buffer.'system was'-the objective to have
 a leaching medium that is applicable to.
 biological testing. Although the acetate
 buffer system will complicate biological
 testing, it should  not preclude bioassajf'
 evaluation of TCLP extracts entirely.
   Phase HI of the TCLP development
 program involves an evaluation of
 ruggedness and precision as well as a
 multi-laboratory  collaborative study.
 Since the design  of these studies, and
'•' hence the results.are a function of how
 EPA addressed some of the operational
 aspects of the EP, a discussion of Phase
 III follows the next section which
 presents and discusses some of these.
 procedural problems.              ;

 6. Operaticinal Aspects         '   :.  • "
   As indicated previously, in moving
 from the E!? to .the" TCLP protocol, the •
 Agency hoped to improve the test
 procedure and eliminate some steps in  •
  the EP procedure which have caused
  difficulty for analysts. These include  the
  need .for continual pH adjustment, which
  is time consuming and serves as a
  source of imprecision, and the difficulty _
  in performing the.initial and finatliquid/ ,
 . solid separations, which currently
  involves 0.45 ptm pressure filtration.,In  ,
  addition, the need to adequately prevent
  volatilization of  organic qompounds .  ,
' during extraction was. critical. These
  three aspects of  the.test procedure are
  discussed ielow. As an aid, Table D-2
  presents a comparison between the EP
  and the.TCLP, in terms of procedural
  aspects. Figures  D-1 and D-2 present
  the flow diagrams for each procedure,
  respectively.           ;

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21678
           federal Register / Vol.
                                                                                               /ProPosed Roles
TABLE  D-2.—COMPARISON OF  THE EXTRAC-
   TION PROCEDURE (EP)  AND  THE TOXICITY
   CHARACTERISTIC   LEACHING    PROCEDURE
   (TCLP)»
     Hem
(t) Leaching
  media.
(2) Uqukt/soW
  sepirition.
                    EP
0.5 N AceUc acid
  added to
  disUlcd
  detonlzed wafer
  loapHof 5
  with 400 ml
  maximum
  addiSon.
  Continual pH
  ndjuslmonL
(MS inn Filtration
  to 7S pa in 10
  pa increments
  Unspecified fitter
  type.
                                   TCLP
0.1 pH 2.9 acetic
  acid solution for  '
  moderate to high
  alkaline wastes
  and 0.1 pH 4.9
  acetate buffer for
  other wastes.
0.6-0.8 urn Glass
  fiber filter filtration
  to 50 psi.
                                  TABLE D-2.—COMPARISON OF THE EXTRAC-
                                    TION  PROCEDURE  (EP)  AND THE TOXICITY
                                    CHARACTERISTIC   LEACHING   PROCEDURE
                                    (TCLP)'—Continued        .    	
Item
(3) Monolithic
material/
particle size
reduction.

(4) Extraction
: vessels.





(5) Agitation.:.- 	



EP
Use of Structural '
Integrity
Procedure or '
grinding and
milling.
Unspecified
design. Blade/
stirrer vessel
acceptable.



Prose definition ol
acceptable
agitation.

TCLP
Grinding or milling
only. Structural
Integrity
Procedure no!
used.
Zero-headspace
vessel required for
volatiles. Bottles
used for non-
volatitesl Blade
stirrer vessel not
used.
Rotary agitation only
in an ehd-over-
end fashion at
30±2 rpm.
                                                                  TABLE D-2.—COMPARISON OF THE EXTRAC-
                                                                    TION  PROCEDURE (EP)  AND  THE, TOXICITY
                                                                    CHARACTERISTIC   LEACHING   PROCEDURE
                                                                   • (TCLP)'— Continued ""    '.''"''
Item
• (6) Extraction
time.
(7) Quality
control
requirements.
.




	 , . EP


Standard additions
required. One
tilunk per
sample batch. . '


- •>

. . „, TCLP ,


Standard additions
required in some
cases. One blank
per 1.0 extractions
and every new:
batch of extract.
Analysis specific
to analyte.
                                                                                                 1 All other attributes between the two tests are generally
                                                                                               the same, although there are some minor differences. Note
                                                                                               also that while the  EP only addresses those species for
                                                                                               which National Interim Primary  Drinking  Water Standards
                                                                                               (NIPDWS) exist, the TCLP can be applied to other toxicants.

                                                                                               BILLING CODE 6560-SO-M

-------
[ Federal Register / Vol. 51, No. 114 / Friday. June 13;:1986 / Proposed Rules'
21679

•._••• -- • .:'•••••:'•" -' - •'- ;'-" .-.-..-•-.-•• •_..- . •
Wet Waste Sample' Representative
Contain^ G.5% . ' Waste Sample
Nonfilte
Solids
J
rable ^ .> IUU brams /
4,
Dry Waste Sample
r • • . - . • •
Liquid Solid i. .
Separation - ™ .
.•.:•'•'- . ' • ' _L "
Liq
Discard
•'.-o'^- ::•:'::•.:•":,?
uid Partic
> 9.5mm < 9.!
Sample Size
Reduction


. * . ' .
.. ' . ' . . .
r ' '• . - '•-."'•'
e'Size .,'..' ; •':...•-..'...'•
•'."-"..• '- .
,
5mm. Monolithic
..'•'-. Structural
Integrity
Procedure

" . ' ' •;•,• A • • - -

' . "-• :'-:J: •••••-' : 4 . .: ' ./''•' -'. ••:.-'.
Solid 4~~ Liquid Solid Separation - -
Discard
, Liq
' J
EPE
" •' . . .-.: '• ' .' J
' ' . . .^ • ' ' "

V' ••.•-•':
uid
It '
1 ' : .
Ktract
Methods ,
. • .
Wet Waste Ssimple
Contains > 0.5%
Nonfilterablei
Solids !
'. - 1 .'[•••-••':'.
Liquid Solid
Separation
" ./"Liq
Store
at pH

uid" f ;;_• -.-.:''.' . •; ; '"(•• . ', :
• ---'-- ' . • - '
St4°C :
— • O' "•'"'" • " j •
•
• i • •-',.'• .'-•'• •
' -• • . '••'.' • >.-'" "
••'•-. ' ' - ' , .
      -Figure D-2:   Extraction Procedure  Flowchart

-------
 21680
Federal Register / Vol. 51. No. 114 / Friday. June 13,1986 / Proposed Rules
                            FIGURE D-2: "TC-LP Flowchart
  WET WASTE SAMPLE
  CONTAINS < 0.5 %
  NON-FILTERABLE
  SOLIDS
   LIQUID/SOLID
    SEPARATION
    0.6-0.8 urn
   GLASS FIBER
     FILTERS
                REPRESENTATIVE WASTE
                       SAMPLE
                                    CRY. WASTE
                                   -' SAMPLE
       DISCARD
        SOLID
                                                   SOLID
SOLID
                       REDUCE PARTICLE SIZE  IF  >9.5 mm
                           OR SURFACE AREA <3.1 cm2
                               TCLP EXTRACTION1
                                   OF SOLID
                            0-HEADSPACE EXTRACTOR  '
                            REQUIRED FOR VOIATILES
                                 LIQUID/SOLID
                                  SEPARATION
                               0.6-0.8 urn GLASS
                                 FIBER FILTERS  ,
                              WET WASTE SAMPLE-
                              CONTAINS > 0.5 •%
                              NON-FILTERABLE
                              SOLIDS
                                          DISCARD
                                           SOLID
                                     LIQUID'
                                   TCLP EXTRACT
            TCLP EXTRACT
                  ANALYTICAL
                   METHODS   •
                                                     LIQUID/SOLID
                                                      SEPARATION
                                                      0.6-0.8 urn
                                                      GLASS FIBER
                                                        FILTERS
                                                                       .LIQUID
                                                                       ."~T~"
                                                                       STORE AT
                                                                         4°C
                                                 	TCLP EXTRACT	._
 1 The extraction fluid employed  is a function of. the alkalinity of the-solid-
   phase of the waste.                                        -         ,  r
BILLING CODE 6560-50-C

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                     Federal Register / Vol. 51. No. 114 / Friday, June 13.1986 /Proposed Eules
   The EP procedure involves continual
 pH adjustment or titration. The
 procedure calls for periodic pH
 adjustments if necessary, at 15 minute
 intervals for up to 6 hours or more. This
 is very tedious, time consuming and
"expensive,-and is also probably the
• single most important element in the EP
 protocol contributing to variability.
 .Using pre-defined leaching media
 eliminates the problem of pH adjustment
 since such media does not require pH
 adjustment during extraction.  ,
   .The initial liquid/solid separation  -...
: problems are.due to the tendency for
 some materials, such as certain types of
 oily wastes, to clog the 0.45 um filter,
; and prevent filtration- even if  •
 ;cdnsiderable.pressure (75,psi) is  applied.
 This problem is serious, since materials '.•
 which do not pass the 0.45 um filter are
  treated as solids e'ven if they physically
  appear to be a liquid. These (liquid)
  wastes are then carried through  EP
  extraction as a solid.
    This is particularly serious for oily
  wastes, since oils have been known to
  frequently migrate to ground waters. It
  is important for the luquid/solid
  separation to treat, as liquids, those-;-,
  materials which can behave as liquids in
  Ihe environment. It is important to
  recognize, however, that some materials,
  such as many paint wastes and  some
 .oily wastes, while they have.some liquid
   properties, they will generally behave as
   solids in the environment  (i.e., will'not '
   migrate in total).
  :  In addition, since different analysts
   may expend varying degrees of effort in
   accomplishing the liquid/solid
   separation with these waste types, this
   problem also contributes to variability.
   As indicated below, EPA believes that
   the liquid/solid separation technique   :
   that has been developed for the TCLP"
   protocol reduces the variability that was
 ' associated with the EP's liquid/solid
   separation technique, and that  it also
   provides a more adequate
   differentiation between those materials
   that behave as liquids in the
   environment, and those materials which
   behave as solids.
   . Initially, it was felt that this problem
 ,  could be addressed through use of the
   much simplier liquid/solid separation
   technique used in RCRA Test Method
   9095 (Paint Filter Free Liquid Test) (Ref.
   27). This.method involves gravity
  • filtration through a 60 mesh paint filter.
   This test method was promulgated  on
   April 30,1985 (50 FR 18370). It  is
    intended to be a qualitative :
    determination of whether a waste  ,
  • contains any free liquids, and  was
developed in response to bans instituted
on the disposal of liquids in landfills.
  In applying this method to the TCLP,
however, a number of problems were
encountered (Ref. 3). The most serious of
these was the fact that particulates,     .,
which are solids, are capable of passing
through the paint filter in bulk. Using
Method 9095 in the TCLP, would lead to
 these solids being considered as a
 liquid, and thus, not subject to
 extraction/This could lead to an
 artificially high (or low) apparent    ' j
 extract concentration. In addition, the
 amount of liquid the method yields
 varies with how the waste is poured or
 placed in the filter. These two problems •
 negated the use'of Method 9095 in the
 TCLP..  .•:-.•:.''.-''''   '•''  '•"..  ".  '    -,'-•'  .
-'•  To overcome the problems
' encountered with the paint filter         .
 method, EPA has returned to the use of
 pressure filtration to separate the liquid
 from the solid phase of a waste. In
 Devaluating this technique, however,
 several changes have been made which
 will decrease the .time  it takes to   '
 accomplish separation, improve the
 precision of the method, and provide a
 more adequate differentiation between  ,
 those materials which behave as liquids.,
 in the environment, and those which
 behave as solids. These.changes include
 switching from a 0.45 um filter medium '
 'of varying composition, to specifying a-
 0.6-0.8 um glass fiber filter, as well as
  limiting the time spent filtering. The use
  of glass fiber will reduce the possibility
  of adsorption of analytes to the filter
  media. Also, these filters have a much
  higher" throughput and show much .less
  tendency to clog, and  for these reasons,
  allow the use of a pressure of 50 psi
  rather than 75 psi to,accomplish
  separation. Initial experiments indicate
  substantial operational advantages and
  time savings with the  use of glass fiber.
  filters (Ref. 4)..                 ~
   : The third problem deals with the need
  to prevent loss of volatile organic
  compounds during the conduct of the
  procedure. This includes losses during
  initial and final liquid/solid separation,
:  extraction,.and sample handling. With
: the assistance of laboratory equipment
  manufacturers, EPA has addressed this
  problem .through development of a Zero-,.
' Headspace Extractor (ZHE). After
   experimentation:with several prototype
   devices, the device  described
   schematically in Figure D-3 has been
   successfully applied during evaluation
   of the TCLP procedure. Equipment of
   this type is now available from two
   suppliers (See TCLP in the proposed
   Appendix ll to Part 261).
                                                                       21681  '-'•

-------
                             -Filter-
                  "Waste/Extraction Fluid
                             Piston
3
          EEV.
                                                             Top
                                                             Flange
                                                       Body
                    ,VITON
                     O-rings
                     (2 of  three)
                                                 -r
                                                            Bottoni
                                                            Flanne.
           Pressurizing Gas Inlet/Outlet Valve
     Figure  D-3; Zero-Headspace  Extraction Vessel
   The ZHE is capable of conducting the
 initial liquid/solid separation, agitation,
 as well as final extract filtration, with
 only minimal loss of volatiles. Although
 considerably more expensive than the
 bottles used in the current EP, these
 devices are only required when
 investigating the leachability of volatile
 components. Less expensive vessels are
 used for assessing the mobility of non-
 volatile components. In addition, since
 the ZHE is capable of also conducting
 the liquid/solid separation, no
 additional filtration apparatus is
 required.
  Due to the need to have the ZHE
 compatible with common laboratory
 equipment, such as off-gassing ovens,
and laboratory sinks, and also the need
to produce a device that is easily
handled by laboratory personnel, a
device smaller than the 2 liter internal
volume device EPA originally had in
 mind was necessary. Balancing the need
 to also accommodate as large a sample
 size as possible, EPA determined that'a
 device with one-half liter [500 ml)
 internal volume would be more
 appropriate. Due to the 500 ml internal
 capacity, the ZHE can only
 accommodate a maximum sample size
 of 25 grams for "a 100 percent solids
 sample. For a waste of less than 100
 percent solids, the maximum, sample
 size the ZHE can accommodate is .tied to
 the percent solids of the waste. The
 device can only accommodate the
 minimal 100 gram sample size specified
 for bottle extractions for wastes that are
 25 percent solids or less.
  In addition to the major improvements
 discussed above, EPA has instituted a
number of minor Improvements in the
TCLP protocol. These improvements are
primarily designed to increase the
overall precision of the method. For
  example, in transferring samples from
  container to filtration apparatus to
  extractor, etc., the procedure-calls for
  determining the weight of any residual
  sample material left behind and
  subtracting this from the total sample
  size, this will insure that the amount of
  extracting medium added to the '
  extractor is truly a function of the solid
  .material within the extractor, and will
  help to improve overall precision.
  7. Results of Phase III

    Phase III of the TCLP development
  program involved an evaluation of
  ruggedness and precision as well as a
  multilaboratory collaborative study. The
  experimental design and a summary of
  the results of the precision evaluations
  are presented below. While the
  ruggedness evaluation for the metals
  and semivolatiles have been completed
  the work on the volatiles portion of the
  method is in progress. The results of the
  ruggedness evaluation for the volatiles
  will be noticed for comment upon
  completion.
   EPA's collaborative study is currently
  on-going. In addition, the Electric Power
  Research Institute (EPRI) has conducted
  a limited collaborative evaluation of the
  draft TCLP protocol, primarily as it
  appies to inorganic constituents. The,
  report on this study is being drafted. The
  results of .both of these studies will be
  noticed for comment when completed.
   a'. Precision evaluation. As discussed
  earlier, the TCLP protocol requires the
 use of a Zero-Headspace Extractor
 (ZHE) when dealing with vplatiles, and
 the  use of common EP extraction
 equipmenmt (i.e., bottles) when dealing
 with non-volatile components. In
 response, EPA has conducted a
 precision evaluation of the TCLP
 protocol using both devices. These'
 evaluations xvere conducted by two
 laboratories, each laboratory conducting
 a number of replicate extractions on two
 wastes. These wastes were an API
 separator sludge/electroplating  waste
 admixture containing nonvolatile
 organics and a variety of inorganics, and
 an ammonia still lime sludge containing •
 a variety of polycyclic aromatic
 hydrocarbons, and several inorganic
 compounds. These wastes were  also
 spiked with several volatile compounds.
  The results of the precision evaluation
 for non-volatile components indicate the
 TCLP to be of acceptable precision (Ref.
 23). For the most part, the percent
 coefficient of variation between
 replicate extractions for individual
 constituents was less than 30 percent.
This includes the variability contributed
by sampling variability,and analytical
variability. Although sampling

-------
                    Federal Register / VoL 51, No. 114'/
                                                                                                               21683
variability was minimized to the extent
possible, iir is reasonable- to expect a
sample variability contribution to the;,
total variability of between 2 and 5
percent. Analytical variability was in
many cases comparable to, and in some
cases exceeded, the total variability.
This observation is significant as the
 analytical methods used to analyze me
 TCLP extracts are well accepted and -in
 widespread use,                „.:..
   Precision for tha non-volatiles was
 observed to be best for those
 contaminants present at relatively high
 levels, as is- the usual case to any.
 analysis, for method precision. For those
 cases; where the contaminant wps.   .
 present at relatively low concentrations,
 precision was-pair, the percent    .
 coefficient of variation generally tailing
 below 50 and 60 percent.
    The results of the precision
  evaluations for the volatile components
  [Ref. 9), are not as clearly inteipr.eted.
  There are several reasons for this>. These
  evaluations were' initiated as the zero-
  headspace extractor became available,
  Recall that the present design for the
  ZHE was. the result oi experimentation, - .
  with several prototype deuces. Hence,-
  experience with the ZHE, especially by
  laboratory technicians who were
  responsible for conducting the  work was
  limited.-
     In addition, the precision work on the
  volatiles was conducted using two draft
 , TCLP protocols. The first publi|araft
  protocol was released for comment In
  April of 1985. At this time EPA was still
  experimenting with several proto^e,
  devices, and although the April TCLP
  draft addressed volatile components,, it
  was largely to obtain technical^
  comments and suggestions.ancF was not
  based_pn an actual working ZHE device.
  It was"this; protocol under whicji the
  TCLP precision evaluation of tjre
-   volatiles was begun.        :"-.-- „
     The second public draft of thejTCLP
   protocol was released for comment in
   October of 1985, Although this draft was
   based on the current design for tWZHE,
   further experience with the device ias
   led EPA to re-write the TCLP  volatiles
   procedure in the form that it currently
   appears (see TCLP in the proposed
   Appendix II to Part 261). In addition,  it is
   possible that further clarifications in  the
    procedure.may be advisable.^.   __.  ;
     The remainder of the precision
    evaluation for the volatiles w§s, _
    conducted using the Octobe&pp® draft
    TCLP. Several significant change&have,
    been made in the current (proposed)
    version due to experience gained with
    the  device.JFor example, whereas the
    October 1985  version allawerTj^euse of
    VOA vials for the .collection qf thef CLP
     extract, the proposed method requires
the use-of air-tight syringes or TEDLAR®
bags due tc- expected- losses of volatiles
from the VOA vials during collection of
the extract. VOA vials-were used to-
collect the  extract during the precision
evaluation of the volatiles.        •  .
  Also, in following the protocols,
inadvertent errors were apparently   •
made which seem to have affected
method precision. For example, whereas
the October 1985 version of the protocol
placed a maximum of 25- grams on the
amount of solid material the ZHE could
accommodate, considerably more solid
material was extracted during the
precision analysis of one of the wastes
tested (i.e.» the API separator sludge/
electroplating waste admixture). This
provided for a variable liquid to solid,
ratio rather than the specified 20 to 1
ratio.
   To complicate matters further, due to
 extenuating circumstances, two
 individual laboratories conducted the
 work rather than the intended single
 laboratory. It is. apparent that higher
 concentrations were obtained on the
 same waste from the different
 laboratories.              '.
   As indicated above, 'these- factors
 make the precision data difficult to
 interpret. Whereas the percent
 coefficient of variations on the ammonia
 still lime sludge were mostly less than
 60 or 70 percent, which is fair given the
 nature of volatiles, the numbers
 generated from the admixture of API  '
 separator sludge, and: electroplating
, .waste indicated more variability. As,
 indicated in the draft report (Ref. 9),
 some of this can be attributed to severe
 laboratory contamination problems, and
 the oily character of the waste, which
 seemed to have dominated the
 extraction,        .."..-.
   Due to  the inconclusive nature of the
 results, EPA is.in the process of
  conducting another precision evaluation
  of the volatile components. This study
will use-the proposal draft of the TCLP, ,
which we believe should help to clear
up some of the problems encountered
during the first evaluation.'This study  v
will be similar to the pre-wious one in .
most other aspects, except that a third
waste will be evaluated (one expected
to not react with the spiked volatiles),
and two levels of volatile spike- will be .-
used (i.e., one erf relatively high
concentration and one of relatively tow
concentration^ The results, of this
evaluation will be noticed for comment
upon its completion.        '.--...
.  'b.:Ruggedites.s evaluation, A.
'ruggedness. evaluation is designed to
determine how sensitive; a test method
is with respect to modest departures
from, the protocol which can be expected
 during routine applications; of the
 protocol. The purpose of this evaluation
 is to identify procedural variables which
 must be carefully controlled, and then to
 emphasize in the protocol the limits of
 acceptable delation with respect to
 these, variables. If a procedure is.  .
 "ragged" it will be unaffected! by minor
 departures from the specified method
 values. If results are affected by
 variation/of conditions, the protocol
 must be written to specify those
 parameters which must not be varied
 beyond a deteirmined amount.
    As with the precision evaluation,
 ruggedness was evaluated for both the.
 ZHE and common EP extractorJjottles.
 Different lots "of the same wastes used
 for the precision evaluations were used
 • for the ruggedness evaluation. These
 evaluations: Were performed by one
 laboratory. Vsfhereas the ruggedness
 evaluation for the common EP extractor
 bottles has been completed [Ref. 4a), the
  ZHE evaluation is still in progress.
 Table D-3 presents the parameters
•  which were evaluated for ruggedness
  using both types of extraction
 'equipment,  ;  , ...   ,
        TABLE D-3.—PARAMETERS INVESTIGATED DURING TCLP-RuGGEDNESS:EvALUATroN
Parameter
(1) Liquid/Solid ratio.: 	 .- 	 ,•••
(2) Extraction time- 	 - 	 ••
(3) Headspace: . .
ZHE 	 , 	 ~ 	 	 •* 	 -. 	 ••
(4) Medium #1 acidity (milliequivalents
acid). '.-
(5) Medium #2 acidity fmilliequivalents
. acid). .
(6) Aliqucts, (laRing of. ahquots directly
from ZHE for analysis.
(8) Acid wash filters 	 , 	
(9). Filter type — : — 	 	 ., 	 v-...
(10). Pressurizatibn of ZHE during' agita-
tfon (psi).
. TCLP specification

18 	 :, 	 ,•••.•"••••
arci;.;^^,.:.,.^U.;..,,...'..::.'..
70. 	 	 ;...... 	

Allowed for ZHE in some
cases (see .proposed
TCLP). . '
(See proposed TCLP) 	 -
Required; for metals .., 	
.0.6-0.8 .um. glass fiber,. 	 -

'•' •; ZBEdevfce . _
19 to 2i;^.....:..--.l^....-;v-.;"
a to 5 peicent......::..:..'........-....-.
eo to" 8p.:t.;..-.--,..:.....v:................
' . - , °f" ;,.' . '!. '- ^'^' .Jl-
	 T~ ' "jl '.;•" v-5- .*.; - .;; ^ ;-
Associatea ' ' ZHE— Millipbre
'ZHE. ,
0 to 20.H 	 '. 	 	 	

• " ^Common . .
equipment (bottles)
i9-t621."": .
16=10-20, . -. -. '
20 to 60 percent:
'190 to 210.' J-
Borasilicate— Flint '
glass.
Yes-rNo. „ ,.
Polycarbonate—
.Glass fiber.

-------
   21684
                                            VoL 51' No-114 / Friday, June 13, 1986 / Proposed Rules
   TABLE D-S.-PARAMETERS INVESTIGATED DURING TCLP RUGGEDNESS EvALUATioN-Continuec-
            Parameter
  (II) 2HE extract colactfon devtcas..
                                 TCLP specification
                              TEDLAR> bag or syringe	
                                                        ZHE device
                                                  TEDLAR"  bag-syringe	
                                Common
                               ipment (bottl
    There were several parameters which
  EPA intended to investigate (i.e.,
  extraction temperature and agitation
  rate), which could not be accommodated
  due to lack of appropriate laboratory
  equipment necessary to vary these
  parameters. In addition, while EPA had
  originally intended to evaluate the
  effects of different glass fiber filters (See
  Table D-3, Item 9), glass fiber filters
  other than the type specified in the
  TCLP protocol were unable to withstand
  the pressures stipulated in the TCLP.
  Hence, the EP's use of polycarbonate'
  filters were investigated instead. EPA
  has already determined that extract
  concentrations may differ slightly
  between the two filter types (Ref. 4 and
  7), The remainder of the Table D-3
  parameters are largely self-explanatory.
    The ruggedness evaluation for the
  common (EP) extraction equipment
  demonstrated that for the most part, the
  TCLP ii fairly rugged (Ref. 4a). This is
  especially true for the semi-volatile
  organics, which, with few exceptions,
  were unaffected by the parameters
  investigated. For metals, the results
  suggest that at least two parameters are
  critical. As expected, the acidity of the
  extracting fluid directly "influences  the
  extraction of metals. The TCLP protocol
 emphasizes accuracy in the preparation
 of the extraction fluids, by specifying
 the exact recipes for the preparation of
 these fluids, and indicating that the pH
 of these fluids should be accurate to
 within ± 0.05 pH units.
   Bottle type (i.e., borosilicate vs flint
 glass) is the second parameter which
 apparently affects the concentration of
 metals in the extract, and may also
 effect (to a lesser degree), the extraction
 of semi-volatiles. It appears that using
 flint glass can result in significantly
 higher extract concentrations. While
 acid washing the flint glass bottles, or
 an expanded use of blanks, may help to
 solve the problem, specifying
 borosilicate over flint glass would solve
 the problem entirely. Due to the
 substantially higher cost of the
 borosilicate glass (from 3 to 5 times
 higher), EPA is reguesting comment on
 this option.
  The volatiles evaluation for the TCLP
 is currently ongoing. As noted above,
 the Table D-3 parameters were
Investigated to determine if they need to
be controlled more carefully. As an
example, pressurization of the ZHE
   during agitation is being investigated to
   determine whether the buil'd-up of ,
   pressure within the ZHE during agitation
   (which is expected to occur for some
   wastes, particularly carbonate
   containing waste), needs to be
   controlled more carefully. The build-up
   of this pressure could cause the ZHE
  piston to move, thereby causing the
  presence of headspace. The ruggedness
  evaluation would indicate if this
  variable should be controlled more
  carefully, perhaps by putting more
  pressure (e.g., 20 psi) behind the piston
  during agitation.
    As indicated above,  the results of the
  volatiles ruggedness evaluation will be
  noticed for comment upon completion.
    c. Collaborative study. As indicated
  earlier, both EPA and Electric Power
  Research Institute  (EPRI) have planned
  collaborative evaluations of the TCLP
  protocol. EPA's evaluation, in which the
  American Society of Testing and
  Materials, a number of business
  associations and individual companies,
  the Department of Energy, and
  Environment Canada's Environmental
  Research Center are participating, is .
  currently ongoing. This study involves
  26 laboratories, five different wastes,
  both types of extraction equipment, and
  organic arid inorganic compounds,
  including volatiles.
   EPRI's study, which is very similar to
  an evaluation EPRI conducted  on the EP
  (Ref. 2), was limited to the
 determination of inorganic compounds
 and deals with common extraction
 equipment only. This study deals with
 seven types of Utility wastes and
 involves three laboratories. In addition
 to total precision, EPRI is investigating
 the contribution of both variability in
 sampling, and variability introduced
 through analytical methods, as was
 done during the investigation of the EP
 protocal.
   Both studies will be noticed for    '
 comment when completed.
 IX. References
   (1) American Society for Testing and
 Materials (ASTM). Committee D-34 Draft
 Method. Method For 24-Hour Batch-Type
 Distribution Ratio For Contaminant Sorption
 on Soils and Sediments. ASTM D34.02-
 022RO. Philadelphia, Pennsylvania. 1985.
  (2) Electric Power Research Institute
 (EPRI). Proposed RCRA Extraction Procedure:
Reproducibility and Sensitivity.
Environmental Assessment Department. Palo
Alto, California. November 1,1979.
   ,  (3) Energy Resources Company [ERGO).
   EP-HI Preliminary Study. U.S.'EPA Contract
   68-01-6467. September, 1984.
     (4) "Energy Resources Company (ERGO);
   Filtration of Various Wastes Using Various
   Filter Media. U.S. EPA Contract 68-01-7075
   April, 1985..     .              -
     (4a) Energy Resources Company (ERGO).
   Evaluation of Bottle TCLP Draft Protocol.
   Draft Final Report. U.S. EPA Contract 68-01-
   70.75. February 21,1986.
     (5) Environ Corporation. Superfund Risk
   Evaluation Model—Draft prepared under U.S.
   EPA Contract. November 17,1983.
     (6) Francis, C.W. et al. Mobility of Toxic
   Compounds From Hazardous Wastes.
   National Technical Information Service
   (NTIS) PB 85-117-034. Springfield, Virginia.
   August, 1984.                 '••--
     (7) Francis, C.W., and M. Maskarinec. Field
   and Laboratory Studies in Support of a
   Hazardous Waste Extraction Text. Oak Ridge
   National Laboratory Report No. 6247.
   February, 1986.
    (8) Francis, C.W., and M. Maskarinec.
   Leaching of Metals From Alkaline Wastes by
   Municipal Waste Leachate. Oak Ridge
  National Laboratory. Draft Report. January
  1986.                               *
    (9) Francis, C.W., and M. Maskarinec.
  Precision Analysis for the Zero-Head
  Extractor. Draft Report. Oak  Ridge National
  Laboratory. January, 1986.
    (10) Hannack, P. Letter from P. Hannack,
  Canada Ministry of the Environment, Alberta
  Research Center, to T.A. Kimmell, U.S. EPA,
  Methods and Studies Branch  Re: TCLP.
  October 28,1985.
    (11) Harberger, A. C. Three Basic
  Postulates of Applied Welfare Economics: An
  Interpretive Essay. Journal of Economic  •
-  Literature. 9(3):785-797.1971.
    (12) Hicks, J. The Foundations of Welfare
  Economics. The Economic Journal. 49:696-
  712. December, 1939.
   (13) International Agency for Research on
  Cancer (IARC). IARC Monographs on the
  Evaluation of the Carcinogenic Risk of
  Chemicals to Humans, Supplement 4. Lyon,
  France. 1982.
   (14) JRB Associates. Survey of Industrial
  Waste Landfills. U.S, EPA Contract 68-03-
  3113. June, 1985.
   (.15) Just, R.E., D.L. Heath, and A. Schmitz.
  Applied Welfare Economics and Public
 Policy. Prentice-Hall. Englewood Cliffs, New
 Jersey. 1982.
   (16) Kaldor N. Welfare Propositions of
 Economics and Interpersonal Comparisons of
 Utility. The Economic Journal.  49:549-552
 1939.       ,
   (17) Kimmell, T.A. and D. Friedman. Model
 Assumptions and Rationale Behind The
 Development'of EP-III. Presented at the
 American Society for Testing and Materials
 (ASTM) Fourth Symposium for Hazardous
 and Industrial Solid Waste Testing. In Press.
 Washington D.C. 1984.
   (18) Lehman, A.J. and O.J. Fitzhugh  One
 Hundredfold Margin of.Safety. Association of
 Food and Drug Officers, U.S. Quarterly
 Bulletin. Volume 18.1954.
   (19) McKown et al. Development of
Methodology for the Evaluation of Solid

-------
                      Federal Register / VoL 51, No. 114 / Friday. June 15% 1986 /
                                                                            11685
 Wastes. Volume 1. EPA Contract 68-0&-2552.
 January, 1981.       .
   (20) National Researeh Council (NRC).
, Drinking Water and Health. Vol. 4. Safe
 Drinking Water Committee, National
 Academy Press. Washington, D.C. 1982.
   (21) Office of Management and Budget .
 (OMB). Interim Regulatory Impact Analysis
 Guidance. Washington D.C. June, 1981.
   (22) Research Triangle Institute (RTI).
 Regulatory Impact Analysis for Expansion of
 Toxicity Characteristic Under RCR& U.S.
 EPA Contract 68-01-7075. October, 1985,
  • (23) S-Cubed. Precision Evaluation of the
 TCLP Protocol For Non-Volatile Components.
 Draft Report. U.S. EPA Contract 68-03-1958.
 January 1986.
   (24) Spellenberg, S.P. Organic Extraction
 Procedure. U.S. EPA Contract 68-01-614?.
 January, 1982.
  , (25) Technology Applications Inc. (TAI). '
 Statistical Analysis of TCLP Development
 Data. U.S. EPA Contract 68-01-6936. May 28,
 1985.            ;                .
    (26)' U.S. EPA. Background Document,
  Section 261.24, Characteristic of Extraction
  Procedure Toxicity. National Technical
•  Information Service (NTIS) PB 81-185-027.
  Springfield, Virginia, May, 1980.
    (27) U.S. EPA. Test Methods for Evaluating
  Solid Wastes—Physical/Chemical Methods:
  Second ed. Government Printing Office
  (GPO) 055-002-81001-2'. EPA SW-846.
  Washington, D'.C. 1982.
    (28) U.S. ERA. Guidelines for Performing
  Regulatory Impact Analysis. Washington,
  D.C. December, 1983.
    (29) U.S. EPA Science Advisory Board
  (SAB). Report on the Review of EP-HI.
  Washington, D.C. May, 1984.
    (30] U.S. EPA. Background' Document:
  Issues Relating to the Development and Use
  of Reference Doses to Support 40 CFR Part
  268, Land Disposal Restrictions. Washington,
  D.C. November,. 1985.
    (31} U.S. EPA. Acceptable Daily Intake
  Workgroup Paper: Assessing, Risks
  Associated With Systemic Toxicants.
  Washington, D.C. 1985.
     (32) U.S. EPA. Verified Reference Doses
   (RfD's) of the US. EPA. Washington, D.C.
.  1985.  .  .                         '
     (33J U.S. EPA. Background Document For
   Toxicity Characteristic Leaching Procedure.
   Washington, D.C. February, 1986.

   List of Subjects Jnt 40 CFR Parts 261, 271,
   and 302

     Administrative practice and
   procedure, Air pollution control,
   Chemicals, Confidential business
   information, Hazardous materials,
   Hazardous materials transportation,  ,
   Hazardous substances, Hazardous.
   waste,  Indian lands. Intergovernmental
   relations. Natural resources. Nuclear
   materials,. Penalties, Pesticides and
   pests* Radioactive materials, Reey/eliag,
   Reporting, and. reeordkeeping
   requirements, Superfurid, Water
   pollution, control, Water supply, Waste
   treatment and disposal.
  Dated. May 31,1986.
Lee M.Thomas,                -  -         ,
Administrator^
  For the reasons set out in the
preamble, it is proposed to amend Title
40 of the Cade of Federal Regulations as
follows:

PART 261—IDENTIFICATION AND
LISTING OF HAZARDOUS WASTE

  1. The authority citation for Part 261
continues to read as follows;
  Authority: Sees. 1006,2002(a], 3001, and
3002 of the Solid Waste Disposal Act, as
amended by the Resource Conservation and
Recovery Act of 1976, as  amended (42,'U.S.C.
6905, 6912{a), 6921, and 6922).

   2. § 261.24 is revised to. read as
follows:

§261.24  Toxicity characteristic,
   [aj A solid waste exhibits the
characteristic of toxicity if, using the test
methods described in Appendix II or
equivalent methods approved by the
Administrator under the procedures, set
 forth in §§ 260.20 and 260.21,  the extract
 from a representative sample of the
 waste contains any of the contaminants
 listed in Table 1 at the concentration
 equal to or greater than the respective
 value given in that Table. Where the
 waste contains less than 0.5 percent
 filterable solid's, the waste itself, after   •
 filtering using the methodology outlined
 in Appendix II, is considered to. be the
 extract for the purpose of tbis section.
   ib). A solid waste that exhibits the
 characteristic of taxiclty, but is not  .
 listed as a hazardous waste in. Subpart
 D,. has the EPA Hazardous Waste
 Number specified in Table 1 which
 corresponds to the toxic contaminant
 causing it.to be hazardous.

      TABLE 1.—TOXICITY CHARACTERISTIC
    CONTAMINANTS AMD REGULATORY LEVELS
TABLE  tWTOMCITY  CHARACTERISTIC  CON-
  TAMINANTS AND REGULATORY LEVELS—Con-
  tinued   •''..';•
HWNO and contaminant














DOT1 Silver 	 - 	 —
D045— t-,1>T,2-Tetrachloroethane 	
D046— t,T,2i2-Tetruchloroetftane._ 	 -
D047— Tetrachlbroistnyfene.- 	 	 	
D048— 2,3,4.6.-Tetri3chlorophenol 	

D05Q-— 1,1,t:-Trichl ethee 	 ....


D023— ehlordane-.... 	 . 	 	
D025 — Chloroform _ 	
O026— Q-Cf£sQl *_ — , 	 	 — •—

D016" 24-D- 	 —^ 	 	 -
D029— 1,2-Dichlofobenzen®. 	 	 ...
D030— 1,4-Dichtorobenzene 	
O031— 1,2-Dfchloroethane.... 	 — 	 -
D032 — 1 ,1 -Dichloroethylene 	 	 	 ...
D03S— 2,4-Dinitrotoluene — . — -. 	
P034— Heptachlor (and its hydroxide).
nnas — Hexachlorobenzene 	
CWSNO-
1:07-13-1
74-40-38-2
7440-39-3-
7t-43.-2
111-44-4
7440-43-9
75-T5-Cr
56-23-5
57-74-9
108-90-7
67-66-3
1333-82-0
95-48-7
108-39-4'
106-44-5
94-75-7
95-50-t
106-46-7
107-06-2
; 75-35-4
t2t-t4-2
72-20-a
76-44-8
118-74-1
Regufa-
ory level
(mg/D
5.0
s.a
100
O.Q7
OS>5
1.0
14-4
0.07
0;03
1.4-
0.07
s.a
• 10.0
10.0
10.0
t.4
• 4.*
10-A
• a40
O.T
0.13
o.ooa
0.001
0.13
   ' o-, m-, and p-Cresol concentrations are added together
 and compared to a threshold of IDiO-ingA.

   3. Appendix II of Part 261 is revised to
 read as follc.ws:   -
 Appendix II—Toxicity Characteristic
 Leaching Procedure (TCLPJ
   1.0- Scope aad application.
   1.1  The TCLP-JES. designed! to determine the
 mobility/ of both organic and inorganic.
 contaminants present in liqtridr solid, and -
 multtphasic wastes.      .   •          .   "
   1.2  If a tolial analysis of the waste
 demonstrates that individual contaminants
 are not present in the waste, or that they are
 present but ai sack low concentrations that
 the appropriate regulatory thresholds could
 not possibly be exceeded, the TCLP need not
 be ruh'.  .    ;     '                 .
   2.0  Summary ofmethod {See Figure!}.
   2.1  For wastes containing less than a5%
 solids, the waste, after filtration through a
 0.6-0.8 ,fim glass- fiber filter, is- defined as- the
 TCLP extract.-          •
   2.2  For wastes, containing greater than
 " 0.5% solids, fce liquid phase, if any, is
  separated fixira the solid phase and stored for
  later analysiif-The particle size of the solid
  phase is reduced (if necessary}* weighed, and
  extractedi-wi'th- an amount of extraction fluid
  equaf to 2& times the weight of the solid'
  phase. The extraction fluid employed is a
  function-of the alkalinity of the solid phase of
  the waste. A'special extractor vessel is- used
  when testing for volatiles (See Table 1).
  Following extraction, the liquid extract is
  separated from- the solid phase by a6-ff.8 jxm
  glass fiber filter filtration.
    2.3-  If compatible [e.g, precipitate or
  multiple phases will not form on
  combination}, the initial liquid phase of the .
  waste is added to the liquid extract and these
  liquids are analyzed' together. If incompatible,
   the liquids, are analyzed separately and the

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Reter
                                                    51< No- 114 I Friday, Tune 13. 1986 / Proposed Rules
  results are mathematically combined to yield
  volume weighted average concentration.
    3.0  Interferences.
    3,1  Potential interferences that may be
  encountered during analysis are discussed in
  the individual analytical methods.
    4.0  Apparatus and materials.
    4.1  Agitation Apparatus: An acceptable
  agitation apparatus is one which is capable
  of rotating the extraction vessel in an end-
  over-end fashion (See Figure 2) at 30±Z rpm.
  Suitable devices known to EPA are identified
  in Table 2.
    4,2 Extraction vessel:
    4.2.1  Zero-Headspace Extraction Vessel
  (ZME). When the waste is a being tested for
  mobility of any volatile contaminants (See
  Table 1), an extraction vessel which allows
  for liquid/solid separation within the device,
  and which effectively precludes headspace
  (os depicted in Figure 3), is used. This type of
  vessel allows for initial liquid/solid
  separation, extraction, and final extract
  nitration without having to open the vessel
  (See Section 4.3.1). These vessels shall have
  an internal volume of 500 to 600 ml and" be ,
  equipped to accommodate a 90 mm filter.
  Suitable ZHE devices known to EPA are
  identified in Table 3. These devices  contain
  viton O-rings which should be replaced
  frequently.
   4.2.2   When the waste is being evaluated
  for other than volatile contaminants, an  .
  extraction vessel which does not preclude
  headspace (e.g., 2-liter bottle) is used.
  Suitable extraction vessels include bottles
  made from various materials, depending on
  the contaminants to be analyzed and the
  nature of the waste (See Section 4.3.3). These
  bottles are available from a number of
  laboratory suppliers. When this type of
  extraction vessel is used, the filtration device
 discussed in Section 4.3.2 is used for initial
 liquid-solid separation and final extract
 filtration.
   4.3  Filtration  devices:
   4.3.1  Zero-Headspace Extractor Vessel   •
 (See Figure 3): When the waste is being
 evaluated for volatiles, the zero-headspace
 extraction vessel is used for filtration. The
 device shall be capable of supporting and
 keeping in place the glass fiber filter, and be
 able to withstand the pressure needed to
 accomplish separation (50 psi).
   Note. When it is suspected that the glass
 fiber filter has been ruptured, an in-line glass
 fiber filter may be used to filter the extract.
  4,3.2 Filter Holder. When the waste is
 being evaluated for other than volatile
 compounds, a  filter holder capable of
 supporting a glass fiber filter and able to
 withstand the pressure needed to accomplish
 separation is used. Suitable filter holders
 range from simple vacuum units to relatively
 complex systems  capable of exerting
 pressure up to 50  psi and more. The type of
 filler holder used  depends on the properties
 of the material to  be filtered (See Section
 4.3.3). These devices shall have a minimum
 internal volume of 300 ml and be equipped to
 accommodate a minimum filter size of 47 mm.
Filter holders known to EPA to be suitable for
 use are shown in Table 4.
  4.3,3  Materials of Construction:
Extraction vessels and filtration devices shall
be made of inert materials which will not
             leach or absorb waste components. Glass,
             polytetrafluoroethylene (PTFE), or type 31,6
             stainless steel equipment may be used when
             evaluating the mobility of both organic and
             inorganic components. Devices made of high
             density polyethylene (HDPE), polypropylene,
             or polyvinyl chloride may be used when
             evaluating the mobility of metals.
               4.4   Filters: Filters shall be made of
             borosilicate glass fiber, contain no binder
             materials, and have an effective pore size of
             0.6-0.8 um, or equivalent.  Filters known to
             EPA to meet these specifications are
             identified in Table 5. Pre-filters must not be
             used. When evaluating the mobility of metals,
             filters shall be acid washed prior to use by
             rinsing with 1.0 N nitric acid followed by
             three consecutive rinses with deionized
             distilled water (minimum of 500 ml per rinse).
             Glass fiber filters are fragile and should be
             handled with care.
              4.5  pH Meters: Any of the commonly
             available pH meters are acceptable.
              4.6  ZHE extract collection devices:
             TEDLAR® bags or glass, stainless steel or
             PTFE gas  tight syringes are used to collect the
             initial liquid phase and the final extract of the
          •   waste when using the ZHE device.       .  ,
              4.7  ZHE extraction fluid collection
            devices: Any device capable of transferring
            the extraction fluid into the ZHE without
            changing the nature of the extraction fluid is
            acceptable (e.g., a constant displacement
            pump, a gas tight syringe, pressure filtration
            unit (See Section 4.3.2), or another ZHE
            device).
              4.8   Laboratory balance: Any laboratory
            balance-accurate to  within ±0.01 grams may
            be used (all weight measurements are to be
            within  ±0.1 grams).
              5.0  Reagents.
              5.1  Water: ASTM Type 1 deionized,
            carbon treated, decarbonized, filtered water
            (or equivalent water that is treated to remove
            volatile components) shall be used when
            evaluating wastes for volatile, contaminants.
            Otherwise, ASTM Type 2 deionized distilled
            water (dr equivalent) is used. These waters
            should be monitored periodically for
            impurities.
              5.2  1.0 N Hydrochloric acid (HC1) made
            from ACS Reagent grade.
              5.3   1.0 N Nitric acid (HNO3) made from  -
            ACS Reagent grade.
              5.4   1.0 N Sodium hydroxide (NaOH) made
            from ACS Reagent grade.
              5.5   Glacial acetic acid (HOAc) made from
            ACS Reagent grade.
              5.6   Extraction fluid:                •    -
              5.6.1   Extraction fluid #1: This fluid is
            made by adding 5.7 ml glacial HOAc to 500
            ml of the appropriate water (See Section 5.1),
            adding 64.3 ml of 1.0  N NaOH, and diluting to
            a volume of 1 liter. When correctly prepared,
            the pH of this fluid will be 4.93 ± 0.05.
             5.6,2  Extraction fluid #2: This fluid is
           made by diluting 5.7 ml glacial HOAc'with
           ASTM Type 2  water  (See Section 5.1) to a
           volume of 1 liter. When correctly prepared;
           the pH of this fluid will be 2.88 ± 0.05.
             Note.—These extraction fluids shall be '
           made  up fresh daily. The pH should be
           checked prior to use to insure  that they are

             *TEDLAR is a registered trademark of
           DuPont.
  made up accurately, and these'fluids shoijld
  be monitored frequently for impurities. '•'
    5.7 ^Analytical standards .shall be  .
  prepared according to the appropriate      ;
  analytical method.
    6.0  Sample Collection, preservation, and
  handling.
    6.1  All samples shall be collected using a
  sampling plan that addresses the
  consideration discussed in "Test Methods for
  Evaluating Solid Wastes" (SW-846).
    6.2  Preservatives shall not be added to
  samples.               '
    6.3  Samples can be refrigerated unless it
  results in irreversible physical changes to the
  waste.
    6.4  When the waste is 'to be evaluated for
  volatile contaminants, care must be taken to
  insure that these are not lost. Samples shall
  be taken and stored in a manner which
  prevents the loss of volatile contaminants. If
  possible, any necessary particle  size '       '
  reduction Should be conducted as the sample
  is being taken (See Step 8.5). Refer ,to SW-846
  for additional sampling and storage
  requirements when volatiles are   '
  contaminants of concern.
    6.5  TCLP extracts should be prepared for
  analysis and analyzed as soon as possible
  following extraction. If they need to be'
  stored,  even for a short period of time,
  storage -shall be  at 4PC  and samples for   ''
  volatiles analysis shall not be allowed to
  come into contact with the atmosphere (i.e.,
  no headspace).
    7.0 , Procedure when volaliles are not
  involved.
    Although a minimum sample size of 100
  grams is required, a larger sample size may
  be necessary, depending on the percent
  solids of the waste sample. Enough waste
  sample  should be collected such that at least
  75 granis of the.solid phase of the waste (as
 determined using glass fiber filter filtration),'
 is extracted. This will insure that there is
 adequate extract for the required analyses
 (e.g., semivolatiles, metals, pesticides and
 herbicides).              •  •  • ,        .
   The determination of which extraction fluid
 to  use (See Step 7.12) may also be conducted
 at  the start of this procedure. This
 determination shall be on the solid phase of
 the waste (as obtained using'glass fiber filter
 filtration).            ....
   7.1  If the waste will  obviously yield no
 free liquid when subjected to pressure
 filtration, weigh out a representative
 subsample of the waste (100 gram minimum)
 and proceed to Step 7.11.
  , 7.2  If the sample is liquid or multiphasic,
 liquid/solid separation is required. This
 involves the filtration device discussed in
 Section 4.3.2, and is outlined in Steps 7.3 to
 7.9.           ,                      '  .
  7.3   Pre-weigh  the filter and the container   '
 which will receive the filtrate.
  7.4   Assemble filter holder .and filter
 following the manufacturer's instructions.
 Place the filter on the support screen and
 secure. Acid wash the filter if evaluating the
mobility  of metals (See Section 4.4).        '  ".
  7.5   Weigh out  a representative subsample
of the waste (100 gram minimum) and record   '
weight.'        -

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                       Federal Register / Vol. 51.-No. 114 / Friday. June 13.1986 / Proposed Rules
                                                                                 21687
   7.6  Allow slurries to stand to permit the
 solid phase.to settle. Wastes that settle  _
 slowly may be centrifuged prior to filtration.  .
   7.7  Transfer the .waste sample to the. filter
 holder.
   Note.—If waste material has obviously
 adhered to the container used to transfer the  ,
 sample  to the filtration apparatus, determine
 the weight of this residue and subtract it from
 the sample wejght determined in Step 7.5, to :•'
 determine the weight of the waste sample -
, which will be filtered.
 Gradually apply vacuum or gentle pressure of ;
 1-10 psi, until air or pressurizing gas moves
, through'.the .filter. If .this point is not reached
 under 10 psi, and if no additional liquid has •
 passed through the filter in any 2 minute   .
 interval, slowly increase the pressure in 10-
 psi increments to a'maximum of 50 psi. After
 ' each incremental increase of 10 psi, if the
.. pressurizing gas has riot'moved through the
  filter, and if no additional liquid has passed
  through the filter in any 2 minute interval,,
  proceed to the next 10 psi increment. When
  the pressurizing gas begins to move through
  the filter, or when liquid flow, has ceased at  ;
  50 psi [i.e., does not result in any additional
  filtrate within any 2 minute period), filtration
  is stopped.
    Note.—Instantaneous application of high
  pressure can degrade the glass fiber filter,
;  and may cause premature plugging.
    7.8  The  material in the filter holder is
  defined as the solid phase of the wasteland
  the filtrate is defined as the liquid phase.  .
     Note.—Some wastes, such as oily wastes
  and some paint wastes, will obviously
  contain some material which appears to be a
 ; liquid—but even after applying vacuum or
   pressure filtration, as outlined in Step 7.7, this
   material may not filter. If this is the case, the
   material within the filtration device is
   defined  as a solid, and is carried through the
   extraction as a solid.
     7.9  Determine the weight of the liquid
   phase by subtracting the weight of the filtrate
   container (See Step 7.3} from the total weight
   of the filtrate-filled container. The liquid
   phase may now be either analyzed (See Step
   7.15) or  stored at 4°C until time of analysis.
  . The weight of the solid phase of the waste
   sample  is determined by subtracting the
   weight of the liquid phase from the weight of
   the total waste sample, as determined in Step
   7.5 or 7.7. Record the weight of the liquid and
  • solid phases.                 •'.-,.
     Note.—If the weight of the solid phase of
   the waste is less than-75 grams, review Step
 •-  7.0.  ••'"- ,   -:    "'-•.''•• ;•  •-' ; '•"'.••/  '•" '
     7.10  The sample will be handled
  -differently from this point, depending on  '
 •   whether it contains more or less-than 0.5%  •
    solids-. If the sample obviously has greater
    than 0.5%  solids go to Step-.7.il. If it appears
    that the solid may cpmprise less than 0.5% of
    the total waste, the percent solids will be
    determined as .follows:  •  ••              '..
      7.10.1  Remove the solid phase and filter
    fromthe filtration apparatus.           ,
     '7.10.2   Dry the filter and solid phase at
    100±20°C until two successive weighings
    yield the same value. Record final weight.
      7.10.3   Calculate the percent' solids as
    follows:                            ' .
Weight of dry waste and filters minus tared .
     weight of filters divided by initial weight
     of waste (Step 7.5 of 7.7) multiplied by
     100 equals percent solids.
   7.10.4 If the solid comprises less than 0.5%
 of the waste, the solid is discarded and the
 liquid phase is defined as the TCLP extract.
 Proceed to Step 7.14.-     '             .
  , 7.10.5  If the solid is greater than or equal
 to 0.5% of the waste, return to Step 7.1, and
 begin the procedure with a new sample of
 waste. Do not extract the solid that has been
 dried.
   Note.—This step is only used to determine
 whether the solid must be extracted, or    .
 whether it may.be discarded unextracted. It
 is not used in calculating the amount of
 extraction fluid to use in extracting the   .
 waste, nor is the dried solid derived from this
 step subjected to extraction. A new sample
• will have  to be prepared for. extraction". .
   7.11  If the sample has more than 0.5%
 'solids, it is now evaluated for particle size. If
 the solid material has a surface area per gram
 of material equal to or .greater than 3.1 cm2, or
 is capable of passing through a 9.5 mm (0.375
 inch) standard sieve, proceed to Step 7.12. If
 the surface area is smaller or the particle size
 is larger than that described above, the solid
 material is prepared for extraction by
 crushing, cutting, or grinding the solid
 material to a surface area or particle size as
• • described above: When surface area or
  particle size has been appropriately altered,
  proceed to Step 7.12.
    7.12 This step describes the determination
  of the appropriate extracting fluid to use (See
 • Sections  5.0 and 7.0).                     .
    7.12.1  Weigh out a small sub-sample of
 • the solid phase of the waste, reduce the splid
  (if necessary) to a particle size of
  approximately 1 mm in diameter or less, and
  transfer a 5.0 gram portion to a 500 ml beaker
   or erlenmeyer flask.
     7.12.2  Add 96.5 ml distilled deionized
 -  water (ASTM Type 2), cover with watchglass,
   and stir vigorously for 5 minutes using a •. -
7 .  magnetic stirrer. Measure and recoiS the pH.
   If the pH is  < 5.0, extraction fluid #1 is used.
   Proceed to Step 7.13.
     7.12.3   If the pH from Step 7.12.2 is >5.0,
   add 3.5 ml 1.0 N HC1, slurry for 30 seconds,
   cover with a watchglass, heat,to 50°C, and
   hold for 10 minutes.
 ;.    7.12.4   Let the solution cool to room
   temperature, and record pH. If pH is <5.0, use
   extraction fluid #1. If.the pH is > 5.0,   .
   extraction fluid #2 is used.
   -  7.13:  Calculate the  weight of the remaining
   solid.material by subtracting the weight of
   the sub-sample taken  for Step 7.12, from the
   original amount of solid material, as obtained
   from Step 7.1 or 7.9. Transfer remaining solid
   material into the extractor vessel, including
 the filter used to separate the initial liquid
 from the solid phase..                      •
   Note.—If any of the solid phase remains
 adhered to the walls of the filter holder, or
 the container used to transfer the waste, its ,
 weight shall be determined, subtracted from
 the weight of the solid phase of the waste, as
 determined above, and this weight is used in
 calculating the amount of extraction fluid to
iadd into the extractor bottle.
 Slowly add an amount of the appropriate
 extraction fluid (See Step 7.12), into the
 extractor bottle equal,to 20 times the weight
 of the solid phase that has been placed into
 the extractor bottle. Close extractor bottle
 tightly, secure in rotary extractor device and
 rotate at 30 ± 2 rpm for 18 hours; The  -   ^
 temperature shall be maintained at 22 :± 3 °C
 duringfthe extraction period:
   Note.—As agitation continues, pressure    '
 may build up within the'extractor bottle (due
 to the evolution of gasses such as carbon,
 dioxide). To relieve these pressures, the
 extractor bottle may be periodically opened
 and vented intij a hood.    ,.,-  .   .
   7.14  Following the 18 hour extraction, the
 material in the.extractpr vessel is separated
 into its component liquid and solid phases by
  filtering through  a new glass fiber filter as
  outlined in Step 7.7. This new filter shall be
  acid washed (!3ee Section 4,4) if evaluating
  the mobility of metals,
    7.15  The TCLP  extract is now prepared as
  follows:                              •"•'••
    7.15.1  If the waste contained nq  initial
  liquid phase,  the .filtered liquid material   ,
  obtained from Step 7.14 is defined a,s the
  TCLP extract. Proceed to Step 7.16.;
    7.15.2  If compatible (e.g., will not form
  precipitate or multiple phases), the filtered
  liquid resulting n-om Step 7.14 is combined
  with-the initial liquid phase of the waste as:
  obtained in Step 7.9. This combined liquid is
  defined as the; TCLP extract. Proceed to Step
  7.16.    .      -.•  '  - ,       •
     7.15.3  If the initial liquid phase of the .
   waste, as obtained from Step 7.9, is notor
   may not be compatible with the filtered liquid
   resulting from Step 7.14, these liquids are not
   combined. These liquids are collectively     ;
   defined as the TCLP extract, are analyzed
   separately, arid the results are combined
   mathematically. Proceed to Step 7.16.   ;
   ;  7.16  The TCLP extract will be prepared
   and analyzed according to the appropriate
   SW-846 analytical methods identified in   .
   Appendix III 'of 40 CFR 26}. TCLP extracts to _
   be analyzed for metals shall be acid digested.
   If the individual phases are to be analyzed
   separately, determine the volume of the  ;
   individual phases (to 0.1 ml), conduct the '••
  ' appropriate a.nalyses, and combine the-
 • results mathematically by using a simple .
 ; weighted average:
                   Final contaminant concentration=

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    21888
Federal Register /Vol. 51. No. 114 / feday, June 13, 1986 / Proposed Rules
    where:
    Vi =The volume of the first phase W
    Ci=The concentration of the contaminant of
       concern in the first phase (mg/1)
    V3 =The volume of the second phase (1)
    Cist The concentration of the contaminant of
       concern in the second phase (mg/1)
     7.17  The contaminant concentrations in
    the TCLP extract are compared to the
    thresholds identified in the appropriate
   regulations. Refer to Section 9 for quality
   assurance requirements.
     8,0  Procedure when volatiles are
   involved.
     The ZHE device has approximately a 500
   ml internal capacity. Although a minimum
   sample size of 100 grams was required in the
   Section 7 procedure, the ZHE can only
   accommodate a maximum 100 percent solids
   sample of 25 grama, due to the need to add an
   amount of extraction fluid equal to 20 times
   the, weight of the solid phase. Step 8.4   '
   provides the means of which to determine the
   approximate sample size for the ZHE device.
    Altliouoh the following procedure allows
   for particle size reduction during the conduct
   of the procedure, this could result in the loss
   of volatile compounds. If possible, any
   necessary particle size reduction (See Step
  8,5) should be conducted on the sample as it
  is being taken. Particle size reduction should
  only be conducted during the procedure if
  there is no other choice.
    In currying out the following steps, do not
  allow the waste to be exposed to the
  •ilmosphere for any more time than is
  absolutely necessary.
    8.1  Pre-wefgh the (evacuated) container
  which will receive the filtrate (See Section
  4.6), and set aside.
    8.2  Place the ZHE piston within the body
  of the ZHE (it may be helpful to first moisten
  me piston O-rings slightly with extraction
  fluid). Secure the gas inlet/outlet flange
  (bottom flange) onto the ZHE body in
  accordance with the manufacturer's
  instructions. Secure the glass fiber filter
  between the support screens and set aside
  Set liquid inlot/oullct flange (top flange)
      .
   8.3   If the waste will obviously yield no
 free liquid when subjected to pressure
 filtration, weigh out a representative
 subsumple of the waste (25 gram maximum-
 Sec Step 8.0). record weight, and proceed to
 Step 8.5.
   8.4  This step provides the means by
 which to determine the approximate sample
 size for the ZHE device. If the waste is liquid
 or mulliphasic, follow the procedure outlined
 m Steps 7.2 to 7.9 (using the Section 7
 filtration apparatus), and obtain the percent
 solids by dividing this weight of the solid
 phase o;f the waste by the original sample
 size used. If the waste obviously contains
 greater than 0.5% solids, go to Step 8.4.2. If it
 appears  that the soli'd may comprise less than
 0.5% of the waste, go to Step 8.4.1.
   8.4.1   Determine the percent solids by
 using the procedure outlined in Step 7.10. If
 the waste contains less than 0.53i solids,
 weigh out a new loo gram minimum
 representative sample, proceed to Step 8 7
and follow until the liquid phase of the waste
is filtered using the ZHE device (Step 8.8).
 fhfs liquid filtrate is defined as the TCLP
                      extract, and is analyzed .directly. If the waste
                      contains greater than or equal to 0.594 solids,
                      repeat Step 8.4 using a new 100 gram
                      minimum sample, determine the percent  ' »
                      solids, and proceed to Step 8.4.2.
                        8.4.2  If the sample is < 25% solids, weigh
                      out a new 100 gram minimum representative
                      sample, and proceed to Step 8.5. If the sample
                      is > 25% solids, the maximum amount of   '
                      sample the ZHE can accommodate is
                      determined by dividing  25 grams by the
                      percent solids obtained from Step 8.4. Weigh
                      out a new representative sample of the
                      determined size.
                       8.5  After a representative sample of the
                      waste (sample size determined from Step 8.4)
                      has been weighed  out and recorded, the
                      sample is now evaluated for particle size (See
                      Step 8.0). If the solid material within the
                      waste obviously has a surface area per gram
                      of material equal to or greater than 3.1 cm2,
                      or is capable of passing through a 9.5 mm
                      (0.375 inch) standard sieve, proceed
                      immediately to Step 8.6.  If the surface area is
                      smaller or the  particle size is larger than that
                     described above, the solid material which
                     does not meet  the above criteria is separated
                     from the liquid phase by sieving (or
                     equivalent means), and the solid is prepared
                     for extraction by crushing,  cutting, or grinding
                     to a surface area or particle size as described
                     above.
                      Note.—Wastes and appropriate equipment
                     should be refrigerated, if possible, to 4°C
                     prior to particle size reduction. Grinding and
                     milling machinery which  generates heat shall
                     not be used for particle size reduction. If
                     reduction of the solid phase of the waste is
                     necessary, exposure of the waste to the
                     atmosphere should be avoided to the extent
                     possible.
                     When surface area or particle size has been
                     appropriately altered, the solid is recombined
                     with the rest of the waste.
                      8.6  Waste slurries need  not be allowed to
                    stand to permit the solid phase to settle.
                    Wastes that settle slowly shall not be
                    centrifuged prior to filtration.
                     ' 8.7  Transfer the entire sample (liquid and
                    solid phases) quickly to the  ZHE. Secure the
                    filter and support screens  into the top flange
                    of the device and secure the top flange to the
                    ZHE body in accordance with the
                    manufacturer's instructions. Tighten all ZHE
                    fittings and place the device'in the vertical
                    position (gas inlet/outlet flange on the
                    bottom). Do not  attach the extract collection
                    deviqe to the top plate.
                      Note.—If waste material has obviously
                    adhered to the container used to transfer the
                    sample to the ZHE, determine the weight of
                    this residue and  subtract it from the sample
                    weight determined in Step 8.4, to determine
                    the weight of the waste sample which will be
                    filtered.
                    Attach a gas line to the gas inlet/outlet valve
                    (bottom flange), and with the liquid inlet/
                    outlet valve (top  flange) open, begin applying
                   gentle pressure of 1-10 psi  (or more if
                   necessary) to slowly force all headspace out
                   of the ZHE device;. At the first appearance of
                   liquid from the liquid inlet/outlet valve,
                   quickly close the valve and discontinue
                   pressure.
                     8.8  Attach evacuated pre-weighed filtrate
                   collection container to the liquid inlet/outlet
    value-and open valve. Begin applying gentle
    pressure of 1-10 psi to force'the liquid phase
    into the filtrate collection container. If no
    additional liquid has passed through the filter
    in any 2 minute interval, slowly increase'the'
    pressurejn 10 psi increments to a maximum
    of 50 psi. After each incremental increase of
    10 psi, if no additional liquid has passed'
    through the filter in any 2 minute interval,
    proceed to the next 10 psi increment. When
    liquid flow has ceased such that continued
    pressure filtration at 50 psi does not result in-
    any additional filtrate within any 2 minute
    period, filtration is stopped. Close the liquid
    inlet/outlet valve, discontinue pressure to the
    piston, and disconnect the filtrate collection
    container.
     Note.—Instaiitanepus application of high
   pressure can degrade the glass fiber filter and
   may cause premature plugging.
     8.9  The material in the ZHE is defined as
   the solid phase of the wasteland the filtrate
   is defined as the liquid phase.
     Note.—Some wastes, such as oily wastes
   and some paint wastes, will obviously
   contain some material which appears to be a
   liquid—but even after applying pressure
   filtration, this material will not filter. If this is
   the'case,, the material within the filtration
   device is defined as a solid, and is carried
   through'the TCLP extraction as a solid.    '
   If the original waste contained less than 0.5%
   solids, (See Step 8.4) this filtrate is defined as
   the TCLP extract, and  is analyzed directly—
   proceed to Step 8.13.
    8.10   Determine the weight of the liquid
  phase by subtracting the weight of the  filtrate
  container (See Step 8.1) from the total weight
  of the filtrate-filled container. The liquid
  phase may now be either analyzed (See Steps
  8.13 and 8.14), or stored at 4°C until time of
  analysis. The weight of the solid'phase of the
  waste sample is determined fay subtracting
  the weight of the liquid phase from the weight
  of the total waste'sample (See Step 8.4).
  Record the final weight of (lie liquid and solid
  phases.
    8.11  The following details how to add the
  appropriate amount of extraction fluid to the
'  solid malerial within the ZHE and agitation'
  of the ZHE vessel. Extraction fluid #1 is used
  in all cases {See Section 5.6).
    8.11.1' With the ZHE in the vertical
  position, attach a line from the extraction
  fluid reservoir to the liquid inlet/outlet valve.
  The line used s.hall contain fresh extraction
  fluid and should be preflushed with fluid to
  eliminate any air pockets'in the line. Release
 gas pressure on the ZHE piston (from the gas
 inlet/outlet valve), open the liquid inlet/
 outlet valve, and begin transferring extraction'
 fluid (by pumping or similar means) into the
 ZHE. Continue pumping extraction fluid into
 the ZHE until the amount of fluid introduced
 into the device equals 20 times the weight of
 the solid phase of the  waste that is in the
 ZHE.       ,           '
.   8.11.2   After the extraction fluid has been
 added, immediately close the liquid inlet/
outlet valve, and disconnect the extraction
fluid line. Check the ZHE to make sure that:
all valves are in their closed positions. Pick
up the ZHE and physically rotate the device
in an end-over-end fashion 2 or 3 times.

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                        Federal Register!/ Vol. 51, No, 114 /Friday. June 13,1986 / Proposed
                                                                                 : 21689
 Reposition the ZHE in the vertical position-
 with the liquid inlet/outlet valve on top. Put
 5-10 psi behind the piston (if necessary), and
 slowly open the liquid inlet/outlet valve to
'bleed out any headspace (into a hood) that
 may have been introduced due to the
 addition of extraction fluid. This bleeding
 shall be done quickly and shall-be stopped at '
 the first appearance of liquid from the valve.
 Re-pressurize the ZHE vyith 5-10 psi and
 check all ZHE fittings to insure that.they are
 closed.
    8.11.3  Place the ZHE .in the rotary
 extractor apparatus (if it is not already there},
 and rotate the ZHE at 30 + 2 rpm for 18   _
 hours. The temperature shall be maintained
• at 22 Br + 3°G during agitation. -   .-.,.."'
    812  Following the 18 hour extraction,
  check the pressure behind the ZHE piston by
  quickly opening-and closing the g&s inlet/
  outlet valve,; and noting the escape'of gas. If
  the pressure has not been maintained (i.e., no
  gas release observed), the device is leaking.
  Replace ZHE O-rings or other fittings, as
  necessary, and redo the extraction! with a
  new sample of waste. If the pressure within
  the device has been maintained, the material
  in the extractor vessel is once again
  separated into  its component liquid and solid
  phases. If the waste contained an initial
  liquid  phase, the liquid may be fipered
  directly into the same filtrate collection
  container (i.e.,  TEDLAR* bag,'gaslight"
syringe) holding the initial liquid phase of the
waste, unless doing so would create multiple
phases, .or unless there is not enough volume
left witHin the filtrate collection container. A
separate filtrate collection container must be
used in these cases. Filter through the glass
fiber filter, using the ZHE device as discussed
in Step 8.8. All extract shall be filtered and
collected if the extract is multi-phasic or if
the waste contained an initial liquid phase.
   Note.—If the glass fiber filter .is not intact
following .agitation, the-filtration device
discussed in the NOTE in Section 4.3.1 may
be used to filter the material witnin  the ZHE,
   8.13  If the waste contained no initial
liquid phase, me filtered liquid material
obtained from Step 8,12 is defined as the
TCLP extract. If th'e waste contained an
initial liquid phase, the filtered liquid   '  - "  •
material obtained from Step 8.12,  and the
initiaLliquid phase (Step 8.8) are collectively
defined as the TCLP extract;   "      ', _  ',
   8.14 The TCLP extract will be prepared
and analysed according to the appropriate
SW-846 analytical methods, as identified in
Appendix HI of 40 CFR  261. If the individual
phases are to be analyzed separately,
. determine.the volume;.pfthe individual   .
 phases (to 0.1 ml), conduct the appropriate
 analyses and combine the results       .
 mathematically by using a simple volume
 weighted average:'     .*'•'''
                   Final contaminant concentration —
   where:   •   . .  .  •    .'   •-'•'•' ,,:   •>". "   :
  :V,- = The volume of the first-phase (1J  ,    •
   C, = The concentration of the contaminant of
       concern in.the*first phase (mg/1)     ,
   V2 = The volume of the second phase (!)
   C2 = The concentration of the contaminani of
       concern in the 'second phasejmg/l)  _.'
     8.15  The contaminant concentrations in
   the TCLP extract are compared to the
   thresholds identified in the appropriate
   regulations. Refer*to Section 9 formality
   assurance requirements.
     9.0  Quality Assurance requiyments,   \
     9.1  All data, including qualitf assurance
  -'• data, should be maintained and available for
   reference or inspection.
     9.2 . A minimum of one blank for every 10
   extractions that have been conducted in an
  1 extraction vessel shall be employed asa
   check to determine if any memory effects
   from the extraction  equipment is occurring.
   One blank shall  also be employed fp^every.
   new batch of leaching fluid that is. made up.
    '  9.3  AH quality control measures described
   in the appropriate analytical methods shall
   be followed.                   ^
      9.4  The method of standard addition shall
    be.employed for each waste type if: 1)
    Recovery of the  compound from spiked splits
    of the TCLP extract is not between 50'and
    150%, or 2) If the concentration of
 constituent measured in tKe. extract is Within ..
 20% of the-appropriate regulatory threshold.;If.
 more than 1 extraction is being rjm;on
 samples of the same waste, the method of .
 standard addition need only be applied once
 and the percent recoveries Applied to. the
 remainder of the extractions.
    9.5   TCLP extracts shall be analyzed
 within the following periods after generation:
 Volatiles—14 days, Semi-volatiles—50 days,
 Mercury—28 days, and other Metals—180
 days.         .               ,,  .,.._,..

      TABLE 1 .—VOLATILE CONTAMINANTS '
   TABLE 1 .—VOLATILE CONTAMINANTS '-
               1  Continued
             Compound
                                   )  CASNO
1.1,2,2-Tetrachloroetriane.
Tetrachloroethylene. ^
Toluene
1.1,1 Tnohloroethane -
1.1.2 Tnchloroethane
Trichloroethyiene      ,_
Trichlorofluoromethane,
1,1.2-Trichloro-1,2,2-frifluoroethane.
Vinyl chloride.
Xylene,
. . ^. , ; Compound , _
°*
Acetone
Acrylonitrile
Benzene.
n-Butyl alcohol.
Carbon disulfide
Carbon tetrachloride
Chiorobenzene.
Chloroform
1,2-Dichloroethane
1 ;1-Dichlor.oethylene
Ethyl acetate'.'
.Ethyl benzene.
EthyJ, ether.
Isobutanol
Methanol
Methylene chldride
Methyl ethyl ketone.
Methyl isobutyl ke)one.
1.1.1 .2-Tetrachloroethane.
CASNO'
67-6.4-1
107-13-1
"71-43-2
71-36-6
75-15-0
S6-23-5
108-90-7
67-6fc3
107-06-2
75-35-4
141-78-6
100-41-4
60-29-7
78-83-1
67-56-1
75-09-2
78-93-3
108-10-1
630-20-6
 79-34-5
 127-18-4
 108^88-3
 71-55-S
 79-00-5
 79-01-6
 75-69-4
 76-13-1
 75-01-4
1330-20-7
  1 Includes compounds ^identified in both, the Land Disposal
 Restrictions'Rute and the Toxicity Characteristic.   .     ,

    TABLE 2.r—SiUitABLE ROTARY AGITATION
-..-,:  :,- :•   i APPARATUS l    '        •-..•
.Company ' ,
Associated Design; :
. and Manufacturih
California, (800).
882-7711. :
Dublin, California, •
(415) 828^010.
Bedford,", '. '
'' Massachusetts, ,
. (800)225-3384:
• Model -
425910
. 410400,

302400
YT30142HW
XXI 004700

Size
(mm)
142
.47

' 142
' 1,42
•• '47

                                                  1 Any device capable of separating th'e liquid from the solid
                                                phase of the was':e is suitable, providing that it is chemically
                                               ..compatibfe with the waste and the constituents to be ana-
                                                lyzed. Plastic devices (not listed .'above), may be used when.
                                               .--only inorganic cortaminants:are of concern. -

                                                  "-  ..TABLE !>.—SUITABLE FILTER  MEDIA '    ""
Company
Whatman :
Laboratory
ProductSi Inc. .' . ".
. ' . Location,
Clifton,
'(201)
New Jersey
773-5800.

'Nominal pore size. '
BILLING CODE 1 5EO-50-M
" ModeL
' GFF
Rore
size '
0.7
_ - - - - ^<- . • • • •


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'21690
'Federal Register'/ Vol. 51, No. f!4 /"Fridav. fune 13.1^86 / Proposed Rules
                             FIGURE Is  "ICLP Flowchart
   WET WASTE SMPLE
   CONTAINS < 0.5 %
   NON-FlJJTERABLB
   SOLIC6
    LIQUID/SOLID
     SEPARATION
     0.6-0.8 urn
    GLASS FIBER
      FILTERS
                REPRESENTATIVE WASTE
                        SAMPLE
                                    DRY WASTE
                                     SAMPLE
        DISCARD
         SOLID
                                                   SOLID
SOLID
                       REDUCE  PARTICLE; SIZE IF >9.5 mm
                           OR  SURFACE  AREA <3.1 cm2
                               TCLP EXTRACTION1
                                   OF SOLID
                            0-HEADSPACE  EXTRACTOR
                            REQUIRED FOR VOIATILES
                                 LIQUID/SOLID
                                  SEPARATION
                               0.6-0.8 urn GLASS
                                 FIBER FILTERS
                                     LIQUID
                              WET WASTE SAMPLE
                              CONTAINS > 0«:5 %
                              NON-FILTERABLE  •
                              SOLIDS
                                           DISCARD
                                            SOLID
                                   TCLP EXTRACT
            TCLP EXTRACT
                   ANALYTICAL
                    METHODS
                                                      LIQUID/SOLID-
                                                       SEPARATION
                                                       0.6-0.8 urn/
                                                       GIASS FIBER
                                                         FILTERS
                                                                        LIQUID
                                                                        ~1   ""'
                                                                       STORE AT
                                                                         4°C  '
                                                 	TCLP EXTRACT	
 1 The extraction  fluid  employed  is a function of the alkalinity of the solid
   phase of  the waste.

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                                                                            Liquid  Inlet/Outlet Valve
         Extraction Vessel  Holder
Figure ii  Rotary Agitation'

• x
J

' '-




1 	
v_



• 'I
.. F
	 —Filter 	 .— 	 -
Waste/Extraction Fluid







•m
Piston




•



^


Body
^

                                                                                                                 Top   •
                                                                                                                 Flanqe
VITON     ,  '
0-rinqs
(2 or three)
                                                                                                                  Bottom
                                                                                                                  Flanqe
                                                                                                                                  *

                                                                                                                                   z
                                                                       Pressurizing Gas I.nlet/Outlet. Valve
                                                                                                                                   'H*
                                                                                                                                   CJ
                                                                   Figure 3;   Zero-Headspace .Extraction-Vessel
                                                                                                                                    Or.
                                                                                                                                    ce
                                                                                                                                    to.
                                                                                                                                    •8

-------
    4. Amend Table 1 of Appendix HI of
  Part 261 to add the following compounds
  and methods in alphabetical order:
  Appendix III—Chemical Analysis Test
  Methods
  TABLE 1.— ANALYSIS METHODS FOR ORGANIC
       CHEMICALS CONTAINED IN SW-846
                                                 TABLE I.—ANALVSIS METHODS FOR ORGANIC
                                                   CHEMICALS CONTAINED IN SW-846—Contin-
                                                   ued
                                                         Compound
                                                                            First edition
                                                                            meth°d(S)
          Compound
                            First edition
                                      Second
                                     mlmod(s>
Banzen© «
OW*)rol>imz«n
-------
Federal Register / Vol. 51, No. 114 / Friday. lune 13, 1986 / Proposed Rules
TABLE 3024 LIST OF HAZARDOUS SUBSTANCES AND REPORTABLE QuANTiTiES-Qpntinued
Hazardous substance ,_, "

Lindane.
Mercury.
, Methbxychlor,
Methylene chloride
Methyl ethyl ketone.
Nitrobenzene .
Pentachlorophenql.
i Phenol
Pyridine
Selenium
Silver.
1 ,1 ,1 ,2-Tetrachloroethane .
1 ,i ,2.2-Tetrachloroethane .
.Tetrachloroethylene.
2,3,4,6-Tetrachlorophenol .
Toluene
Toxaphene.
• 1 ,1.,1 -Trichloroethane
1 .1 ,2-Trichloroethane.
Trichlordethylena.
2,4.5-Trichloro-phenol.
2,4,6-Trichloro-prienol.
2.4.5.TP. ' -
Vinyl chloride .. . ,
. CASRN . - Regulatory synonyms
•-.--.-•" ' . .' ' ' ~*

-
~
7S092 Methane, dichloro-
78933 2-Butanone,
98953 Benzene, nitro-
87865 Phenol, pentachloro. _,
108952 Benzene; hydroxy-
110861
-
630206 Ethane, 1,1 ,1,2-tetrachloro.
79345 Ethane 1122 tetrachloro-
127184 Ethene,'1.1.2,24etraohloro-.
68902 Phenol, ,.2,3,4,6-tetrachlbro-
^08883 Benzene methyl
71558 Methyl chloroform.
79005 Ethane', 1.1,2-trichloro-
79016 TricWoroethene.
95954 Phenol, 2,4,5-trichloro-
88062 Phenol, 2,4,6-lrichloro-
75014 Ethene, chloro- - _
RQ
1
T
1
1*
1'
1000
JP
1000
\*
1*
1*
1'
r
1"
1*
1000
i
r
r
1000
10
10
100
1'
•
Statutory > -
-nrtot ". RCRA
Codef .was,eNo.
1,4 ;0013
4 D009
1,4 D014
2,4 ! D039 '
4 ,0040 .
1,2,4 ! D041
1,2,4 D042
1,2,4 D043
4"' D044
4 D010
4 D011
4 0045
' 2,4 0048'
•; .2,4-" 0047- ' J.
, 4: O04^" ..'••
. 1,2,4' 0049
'• ; ":1,4;, D015 '.-
. 2,4 ! 0050 ,
2,4; DQ51 ..
' '1,2,4' -D6SZ--
• ' 1,4 0053
1,2.4 O054
1,4 .0017
2,3,4: 0055
21693

Category Pounds (Kg)
X
X
X
C
0
C
A
C
X
X
X
X
X
x-' • ••-
A ' .
.c .-• •
'••X ! " '
c ... '
X
c' •
A
A
B
X
1^(0.454)
1(0.454)
1(0.454)
1000(454)
5000(2270)
1000(454)
10»(4.54)
1000**(454)
1*#(0.454)
1**(0.454) .
1(0.454)
1tt(0,454)-
ia(0.454)
1*(0.454)
,... 10(4.54)
1000(454)
: . 1*(0.454)
. 1000(454)
1 #(0.454)
' 1000#(454)
,10#(4.54)
10#(4.54)
100(45.4)
1 #(0.454)
• 	 ; 	 , 	 -. 	 . — — 	 : 	 • . ' l| ',;•'•'•
      Indicates that the, 1-pound RQ is a CERCLA statutory RQ.
{PR Doc. 86-13033 Filed 6-12-86; 8:45 am]
BILLING CODE 6560-50-M   -

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-------