Tuesday
Movember 17, 1981
Part V
Hazardous Wast® Management System:
Identification and Labelling of Hazardous
Waste      -     .

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        .  &K*     .
 56582     Federal Register  /  Vol. 46, No. 221  /
 ENVIRONMENTAL PROTECTION
 AGENCY

 40 CFR Part 261
 [SWH-FRL1950-8]

 Hazardous Waste Management
 System: Identification and Listing of
 Hazardous Waste
 AGENCY: Environmental Protection
 Agency.
 ACTION: Interim final rule and request
 for comments.	
 SUMMARY: The Environmental Protection
 Agency (EPA) is today revising the
 regulations for hazardous waste
 management under the Resource
 Conservation and Recovery Act to
 exempt certain categories of mixtures of
 solid wastes and hazardous wastes from
 the presumption of hazardousnesa
 presently contained in the regulations.
 EPA is taking this action because the
 Agency believes that the risk posed to
 human health and the environment from
 the management of these waste
 mixtures is not substantial, so that
 automatically defining these waste
 mixtures as hazardous is inappropriate.
 This amendment will substantially
 reduce the regulatory burden to those
 persons who would otherwise have
 applied the regulations for hazardous
 waste management to these mixtures.
 DATES: Effective date: November 17,
 1981. Comment date: EPA will accept
 public comment on this amendment until
 January 18,1982.
 ADDRESS: Comments should be sent to
 Deneen M. Shrader, Docket Clerk
 (Docket 3001), Office of Solid Waste
 (WH-SC2), U.S. Environmental
 Protection Agency, 401M Street, S.W.,
 Washington, D.C. 20460.
    Public Docket: The public docket for
 this regulation is located in Room 2711,
 U.S. Environmental Protection Agency,
 401 M Street S.W., Washington, D.C.
 20460, and is available for viewing from
 9:00 am to 4:00 pm, Monday through
 Friday, excluding holidays.
 FOR FURTHER INFORMATION CONTACT:
' RCRA Hotline, toll free  at (800) 424-9346
 or at (202) 554-1404. For technical
 information contact Judith S. Bellin,
 PhJD, Office of Solid Waste (WH-565),
 U.S. Environmental Protection Agency,
 401M Street, S.W., Washington, D.C.
  20480 (202) 755-9187.
  SUPPLEMENTARY INFORMATION:
  I. Background
    On May 19,1980, EPA promulgated
  the first phase of regulations
  implementing the hazardous waste
  management system under Subtitle C of
the Resource Conservation and
Recovery Act of 1976, as amended .
(RCRA). 45 FR 33066 (1980). These
regulations included the identification
and listing of hazardous wastes in 40
CFR Part 261. Section 261.3 of these
regulations (45 FR 33119) defines a
hazardous waste as a solid waste which
(1) exhibits any of the characteristics
defined in Subpart C of Part 261; (2) is
listed in Subpart D of Part 261, and has
not been excluded by application of
§§ 260.20 and 260.22; or (3) is a mixture
of a solid waste and one or more
hazardous wastes listed in Subpart D of
Part 261 and has not been excluded by
application of §§ 260.20 and 260.22. This
latter provision was adopted to prevent
generators from evading Subtitle C
requirements simply by commingling
listed hazardous wastes with non-
hazardous  solid wastes (45 FR 33095),
and because many wastes do indeed
remain hazardous after admixture or
dilution.
  EPA recognized-that a rule
designating all waste mixtures
containing listed hazardous wastes as
hazardous could create some
unintended results (45 FR 33095). It,
could, for example, result in some waste
mixtures being considered hazardous
wastes which do not pose a substantial
hazard to human health or the
environment because they contain only
very small amounts of listed hazardous
wastes. It was felt that many of these
problems could be addressed by using
the petition procedures of §§ 260.20 and
260.22. Moreover, it seemed likely that,
in many cases, the burden of having to
manage,a waste mixture as a hazardous
waste could be easily avoided by
carefully segregating hazardous from
non-hazardous waste. It was further
recognized, however, that these
 solutions may not readily address the
unintended problems brought about by
 this provision, and EPA, therefore,
 expressly invited public comment on
 other approaches for solving these
 problems (45 FR 33095).
   The regulated community has
 contended in comments to the May 19
 regulation that the petition process,
 alone, is not workable because it would
 require excessive numbers of petitions
 to address the myriad of such problems,
 and, therefore, would be too resource-
 intensive for both the regulated
 community and for EPA. In addition,
 they argue that, in many cases, the
 segregation of hazardous and non-
 hazardous wastes needed in order to
 comply with the rule cannot be easily or
 inexpensively accomplished. Finally,
 they claim that mixtures which contain
 only small amounts of listed hazardous
 wastes often do not pose a substantial
threat ,to human health or the
environment, and therefore do not merit
the rigorous regulation required by the
Subtitle C regulations. These
commenters have raised these
arguments particularly with respect to
wastewater mixtures that contain only
small amounts of process wastes, listed
as hazardous under § § 261.31 and
261.32, or small amounts of discarded
commercial chemical products or
manufacturing chemical intermediates
listed under § § 261.33 (e) and (f).
  A second area where the current rule
does not appear necessary involves
mixtures of solid wastes and wastes
which  are listed as hazardous solely
because they exhibit one or more of the
characteristics of hazardous wastes.
Under the current rule these mixtures
are presumed to be hazardous unless
they are delisted, even when they do not
exhibit any of the applicable
characteristics.                 ^
   The Agency is therefore taking action
to exclude from the presumption of
hazardousness certain types of mixtures
of listed hazardous wastes and
wastewaters, and mixtures of solid
wastes and hazardous wastes which are
listed  solely because they exhibit one or
more of the hazardous waste
characteristics.
   The following sections of this
preamble describe the particular types
of mixtures which will be excluded. Any
excluded mixture may still be a
hazardous waste -if it is listed
independently, or if it exhibits a
hazardous waste characteristic.

II. Problems Encountered With
Application of the Current Mixture Rule
 to Wastewater Treatment Facilities
   The Agency believes that the mixture
 rule, as presently drafted, sweeps too
 broadly when applied to all mixtures of
 wastewater and listed hazardous
 wastes.1 Strict application of the mixture
 rule would cause to be hazardous waste
 a mixture of large volumes of non-
 hazardous wastewater and the
 relatively small amounts of listed
 hazardous wastes which are introduced
   'This is not to say that the mixture presumption
 does not have validity in many settings involving
 mixtures of listed wastes'and wastewater. There
 are situations where toxic wastes are mixed with
 wastewaters in concentrations sufficient to render
 hazardous the resulting mixture and wastewater
 treatment sludges, Furthermore, many wastewater
 treatment facilities contain unlined surface
 impoundments, which are of special environmental
 concern when they are used to treat, store, or
 dispose of hazardous waste. Many pollutants are
 water soluble, and impounded wastes are
 constantly exposed to water under conditions
 where a hydraulic head can develop. Hazardous
 constituents are especially available for leaching to
 the environment under these conditions.

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                                                                                                                    56583
  into the wastewater as a result of
  normal manufacturing operations or on-
  site laboratory operations. Resulting
  wastewater treatment sludges would
  likewise be hazardous wastes under
  § 261.3(e}(2}. In many cases, however,
  these relatively small amounts of listed
  hazardous wastes are likely to be
  greatly diluted in the wastewater, so
  that the resulting mixture is not
  hazardous. In addition, hazardous
  constituents of the listed hazardous
  wastes may adsorb to soil, degrade of
  otherwise attenuate during the course of
  wastewater treatment, further reducing
  the potential hazardousness of the
  mixture. A presumption of
  hazardousness is not warranted in these
  situations.
    Data submitted by the Chemical
  Manufacturers Association (CMA) and
  the American Petroleum Institute (API)
  indicate that small amounts of spent
  solvents listed in § 261.31, discarded
  commercial chemical products and
  manfacturing chemical intermediates
  listed in § 261.33, and discarded
  laboratory wastes often are mixed with
  large Volumes of process wastewater in
  a relatively innocuous manner. They
  claim that these practices, in some
  cases, are unavoidable (e.g.,
  unanticipated "spills into a
  manufacturing plant's sewer system)
  and, in other cases, are reasonable and
  efficient practices for managing these
  small volumes of wastes. In addition,
  data from API indicates that relatively
  small amounts  of the sludge resulting
  from cleaning of heat exchangers (EPA
 Hazardous Waste No. K050) often is
 mixed with large volumes-of wastewater
 as a result of reasonable and efficient
 waste management practices, without
 significantly increasing the resulting
 concentration of hexavalent chromium
 in the wastewater.
   Although these data, in some cases,
 show sizable amounts of listed
 hazardous wastes discharged into non-
 hazardous wastewaters, the relative
" quantity of these listed wastes mixed
 into the wastewaters is small,
 oftentimes exceedingly small.
 Consequently, the resulting
 concentration in the wastewafer of the
 hazardous constituents of .the listed
 hazardous wastes are very small. For
 example, 1,1,1-trichloroethane, a solvent
 used in large quantities in petroleum
 refineries for decreasing purposes, has
 been measured in the untreated refinery
 wastewater at 4—283 ppb, averaging 21
 ppb.23 Additionally, sampling  ;
  JData submission of the American Petroleum
 Institute (API), April 3, igBLjUthough the data were
 gathered from only four refineries, API has
 indicated that they are representative of the
 petroleum refining industry.          ;
  performed by the Agency in the
  petroleum refining and pharmaceutical
  industries itwo industries wiih high
  solvent usage) show that their raw
  wastewaters contain an aggregate of
  0.01 and 0.08 ppm, respectively, of the
  carcinogenic 4 solvents carbon
  tetrachloride, tetrachloroethylene and
  trichloroethylene. s 6 Agency data also
  show that the combined concentration
  in the raw wastewater of the listed
  solvents methylene chloride, 1,1,1-
  trichloroethane, chlofobenzene, o-
  dichlorobenzene, and toluene is 0.2 ppm
  in petroleum refineries, and 2.3 ppm in
  the pharmaceutical industry. 3 * 9
    Leaks and other de minimis '
  discharges of § 261.33 chemical products
  or manufacturing intermediates from   ,
  normal manufacturing operations? are
  another source of listed  hazardous
  wastes that are frequently discharged
  into and mixed with non-hazardous
  wastewater, but which appear,to
  contribute little to total pollutant
  loadings. Data provided by CMA for
  several chemical manufacturing
  operations (two facilities processing
  petrochemicals, one producing hydrogen
  fluoride, and one synthesizing
  formaldehyde resins) show that the
  incremental amounts of  § 261.33
  materials reaching the wastewater
  treatment  system as a result of spills,
  leaks, maintenance and laboratory
  activities usually constitute a small    ,
  percentage (in all cases except one less
  than one percent) of the  total amount of
  such materials contained in the
  wastewater influent.10 For example, a
  plastics manufacturing plant using
  acrylonitrile  (a commercial chemical
  product listed in §261.33(f)) discharges
  into its wastewater treatment system
  only 8 Ib per day of discarded
  acrylonitrile  resulting from equipment
  leakage and cleanup, relief-device
  discharges, and line rinsings, whereas
  the quantity of acrylonitrile introduced
  into its wastewaters from the   .
  manufacturing process per se amount to
  800 Ib per day."                -
   On-site laboratory operations also
  often discharge small amounts of listed
  hazardous wastes into a plant's
  wastewater. Many of the commercial
.  chemical products listed in § 261.33 are

   3 Development Document for Effluent Limitations
  Guidelines and Standards for the Petroleum
  Refining Point Source Category, EPA 440/l-79-014b,
  December 1979.            '
   4 EPA's Carcinogen Assessment Group (CAG) has
  determined that there is substantial evidence to
  indicate that these substances are potentially
  carcinogenic in human beings.                .
   '" See footnote 2
   sSee footnotes      '      ,
   'See footnote 3                .'-.."
   8 Development Document for Effluent Limitations
 Guidelines  and Standards for the Pharmaceutical
 Industry Point Source Category, EPA 440/l-8Q-084a,
 June 1980. . '   ,    • .                ••-".-
 either used or analyzed in laboratories.
 Also, laboratory operations typically
 use a variety; of solvents and often
 discharge small quantities of the spent
 solvents listed in § 261131 into a plant's
 wastewater treatment system. An
 industrial laboratory is estimated to
 produce between 20 and 1600 kg of
 hazardous wastes per year.12 A high
 proportion of-these wastes is probably
 discarded to wastewater.
 -:  Another source of listed hazardous
 wastes which 113 mixed into'wastewater
 is of particular 'Concern to the petroleum
 refining industry.13 Refinery operations
 and maintenance activities require
 removal of accximulated residues from
 the cooling water side of heat
 exchangers. These residues are listed as
 a hazardous wsiste (EPA Hazardous
 Waste No. K050). In the course of daily
 cleaning operations, these residues are
 managed most efficiently by. being3
 discharged into the refinery's  ••__••.
 wastewater treatment system. On the
 average, in a typical refinery, about 75-'
 150 kg per year of heat exchanger
 bundle sludges are flushed to the sewer
 system."Dilution of these residues in
 the large volumes of refinery
 wastewater results in very low   _•
 concentrations of total chromium. It is
 estimated that these concentrations are
 almost always less than 1 ppm (usually  '
 much less' than 0.1 ppm).15 Sampling
 performed by tLe Agency at seven
 refineries showed less than 0.05 ppm of
 total chromium.16 Concentrations of
 hexavalent chromium, the species of
 chromium of specific concern because of
 its toxicity, are (estimated to be even
 smaller.       j                     -;.-
  Based on the foregoing evidence, EPA.
 believes there isl a justified heed for
 amending the mixture rule in
 § 261.3(a)(2)(ii) to restrict this rule as it
 applies to wastewater mixtures, so as to
 avoid Subtitle C regulation of
 wastewater mixtures that do not pose  a
 substantial threat to human health or
  9 The presence of these compounds in the
wastewater does not necessarily derive from their
use as sol vents. They may also derive from
manufacturing processes •where the material is used
as a reactant/raw material, rather than as a solvent,
pr from laboratory operations. Increased
concentrations of thtise materials in wastewater
attributable to their use as solvents will thus be less
than the values reported above, reinforcing the
Agency's view thai its contemplated relaxation of
the mixture rule for these materials will not
jeopardize human' health or the environment
  '"Submission of the Chemical Manufacturers
Association [CMA), March 25,1981.    '
  "See footnote 10., '.  "
  12See footnote, 2.'  ;   ..'.'.:-."
  13 See footnote 2. ';"•  '
  "See footnote 2.  J"
  13 Calculated from submission of API (see footnote
2).    ;.-•.-'    ••-._.
  10 See footnote 3.  ";         .-,•:•

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56584
Federal Register  / Vol. 46. No. 221  /  Tuesday, November 17, 1981 / Rules
the environment. In doing this, however,
the Agency must ensure that
modification of the mixture rule will not
allow or encourage generators to
discharge large quantities of listed
hazardous wastes into wastewater
treatment systems to circumvent proper
management of these listed wastes.
Today's amendment is designed to meet
these purposes by limiting the mixture
nils so that, with respect to wastewater
mixtures, it does not apply to non-
hazardous wastewaters that receive
small quantities of listed hazardous
wastes which are not principal
wastewater streams, and which are
reasonably and efficiently managed by
being discharged into a plant's
wastewater treatment system. EPA
believes that the small quantities of
listed hazardous wastes allowed by
today's amendment in exempted
wnstewater mixtures will be present in
such low concentrations that they do not
pose a substantial hazard to human
health pr the environment, and,
furthermore, often will be treated in the
plant's wastewater treatment system."
   Today's amendment (except for
 §261.3(a)(2)(iii)) applies only to
wastewater mixtures managed in
wastewater  treatment systems whose
discharge is  subject to regulation under
 either Section 402 or 307(b) of the Clean
Water Act. This requirement will help to
prevent indiscriminate discharge of
 wastes into wastewater treatment
 systems, because to do so could
 jeopardize the generator's ability to
 comply with its Clean Water Act
 discharge requirements. By the phrase
 "wastewater subject to regulation under
 either Section 402 or 307[b) of the Clean
 Water Act"  used in today's amendment,
 the Agency means to include all
 facilities which generate wastewater
 which is discharged into surface water
 or into a POTW sewer system. The
 Agency also means to include those
 facilities (known as "zero dischargers")
 that have eliminated the discharge of
 wastewater as a result of, or by
 exceeding, NPDES or pretreatment
 program requirements.
   The amendment does not apply to   ,.
 facilities which discharge into privately
 owned treatment works. The Agency
 has no information on the types of listed
 waste and wastewater mixtures
 occurring at these facilities. In addition,
   "Most wastewaters are currently treated by
 chemical or biological treatment processes designed
 to degrade organic materials. Most of the listed
 hazardous wastes covered by today's amendment
 are hazardous because they contain organic
 hazardous constituents. Many of these constituents
 uro capable of being treated by these wastewater
 treatment systems at the concentration allowed in
 today's amendment.
                               they have no regulatory obligation to
                               treat their wastes prior to discharge. The
                               likelihood of indiscriminate mixing of
                               listed hazardous wastes and
                               wastewaters at these facilities is thus
                               greater than in those subject to ••
                               reguation under the Clean Water Act.
                               The privately owned treatment works to
                               which these unregulated facilities
                               discharge, however, may qualify for the
                               mixture rule exclusion provided their
                               own discharge is subject to regulation
                               under the NPDES or pretreatment
                               programs, and provided further that the
                               influent streams to these treatment
                               works meet the relevant exclusion limits
                               contained in today's regulations.
                                  The following sections of this
                               preamble describe the several
                               provisions of today's amendment in
                               more detail.
                               A. Mixtures ,of Wastewater and
                               Hazardous Waste From Non-Specific
                               Sources Listed in 40 CFR 261.31
                                  The Agency believes that, of the
                               hazardous wastes listed in § 261.31, only
                               the spent solvents need be covered by
                               today's amendment because these are
                               the only wastes in § 261.31 that seldom
                               are principal wastestreams, and often
                               are discharged in small quantities into
                               wastewaters as a practical way of
                               managing them. Most of the other
                               wastes listed in § 261.31 are principal
                               .wastestreams generated in
                               manufacturing operations, and typically
                               • would be introduced into
                                wastewatersls in relatively large
                               "quantities.
                                  Spent solvents are generated hi a
                                great many manufacturing and allied
                                operations such as degreasing,
                                maintenance,  extraction, purification
                                and constituent application procedures.
                                (The same substances may also be used
                                in a manufacturing process as chemical
                                reactants or process intermediates, and,
                                when so used, are not considered to be
                                spent solvents.19) It is not always
                                possible to collect and segregate~spent
                                solvents (e.g., various spills or incidental
                                losses from degreasing or maintenance
                                operations); those materials often drain
                                or are washed into wastewater sewer
                                systems. Also, it is. often practical and
                                regonable  to discharge the small
                                quantities of spent solvent generated in
                                diverse and separate manufacturing and
                                allied operations into the nearest sewer
                                connected to  the wastewater treatment
                                system. These small quantities pf spent
solvent are conveniently managed by
and treated in the chemical or biological
wastewater treatment system.
  The Agency has decided to deal with
these situations by amending
§ 261.3(a)(2) to provide that the mixture
rule does not apply to mixtures of
§ 261.31 spent solvents in wastewaters if
the combined concentrations of the
spent solvent in the resulting mixture
are no greater than 1 or 25 ppm,
depending on the type of solvent
(§ 261.3(a)(2)(iv) (A) and (B) of today's -
amendment). The lower limit applies to
those listed spent solvents determined
by the Agency's Carcinogen Assessment
Group (GAG) to possess substantial
evidence of carcinogenicity, namely,  •
carbon tetrachloride,
tetrachloroethylene (perchloroethylene)
and trichloroethylene. The upper limit
applies to the remaining listed spent
solvents which are listed in § 261.31
because they are toxic (T): methylene
chloride, 1,1,1-trichloroethane,
chlorobenzene, o-dichlorobenzene,
cresols, creyslic acid, nitrobenzene,
toluene, methyl ethyl ketone, carbon
disulfide, isobutanol, pyridine, and spent
chlorofluorocarbon solvents.20 The
Agency chose these limits after
considering a number of factors. First, it
concluded that different limits should be
set for these two groups of spent
solvents because the scientific literature
shows a decisive difference among the
concentrations of these solvents in ,
water that produce adverse health and
environmental effects.21 Second, the
 agency considered the  factors listed in
 § 261.11(a)(3) to make a judgment about
 the  concentration of spent solvents for
 each group that if deemed would not
 cause the wastewater mixture, if
 improperly managed, to pose a
                                  is Several of the other wastes listed in § 261.31
                                 are sludgs from wastewater treatment and thereby ^
                                 are derived from rather than introduced into
                                 wastewaters.
                                  10 See Background Document to hazardous waste
                                 listings F001-F005. response to comments,
                                 November 14,1980.
   20The spent fluprocarbon solvents are included in
 this aggregate limitation even though their listing
 rests on a different basis than that of the other spent
 solvents, namely, the threat to the ozone layer after
 volatilization. Limitation of the concentration of
 these solvents in wastewater should, as a practical
 matter, help meet this concern by reducing the
 amount of fluorocarbon solvent available for
 release. The Agency, therefor has tentatively
 determined to include the spent fluorocarbon
 solvents in the aggregate limitation. We do
 however, solicit comments as to whether a separate •
 limit should be adopted for this class of solvents,
 and what this limit should be.
   21 The Water Quality Criteria established by EPA
 under Section 304(a) of the Clean Water Act set
 criteria of 0.8, 2.7 and 0.4 ppb for carbon
 tetrachloride, trichloroethylene and
 tetrachloroethylene, respectively, and set much
 higher criteria (ranging from 0.4 to 19.8 ppm) for
 seven of the substances in the second group of spent
 solvents. The figures cited for the carcinogenic
 solvents are for a 10~ 6 additional cancer risk level
 due to a lifetime exposure from daily ingestion of
 two liter,? of water, and consumption of 6.5 g of fish
 and shellfish. See 45 Fed. Reg. 79318 (November 28,
 1980).

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      21
                                                             Novemoer 17, 1981 / Rules and Regulations   56585
 substantial hazard to human health or
 the environment. An important factor in
 the consideration was the reduction of
 spent solvent concentrations that
 typically would be achieved in the
 treatment of the wastewater mixture
 before its intended or unintended (e.g.,
 subsurface leakage) release into the
 environment. The Agency reasoned that
 virtually all of the wastewater mixtures
 covered by today's amendment will be
 given treatment, and thatthis treatment
 will typically be biological, physical or
 chemical treatment capable of reducing
 the spent solvent concentrations in the
 wastewater, particularly at the low
 concentrations assured by the limits  -
 selected. The Agency concluded that, if
 the spent solvent concentrations in the
 wastewater mixture prior to treatment
 are limited to 1 and 25 ppm, the
 wastewater treatment process will
 typically reduce these concentrations in
 any releases, of the wastewater to levels
 that do not pose a substantial harm to
 human healthjor the. environment,  ,
 Indeed, effluent guidelines data and
 data submitted by API22 indicate that
 wastewater treatment typically reduces
 these concentrations to a range of 10-
 100 ppb, levels that approach the Water
 Quality Criteria^ which the Agency
 considered as a guide in assessing the
 relevant factors.      :
  Spent solvent wastewater mixtures
 may be released before treatment is
 complete. Even in these situations,
 however, other attemiative mechanisms
 such as adsorption to organic soil
 constituents, biodegradation and
 dilution will typically operate to reduce
 the spent solvent concentrations in
•these releases before they are
 transported to points where human or
 environmental exposure may occur.
Thus the Agency'concluded that even
where wastewater releases occur prior
to full treatment, attehuative
mechanisms will reduce spent solvent
concentrations to levels that-will not
pose a substantial hazard to human
health or the  environment when the
influent concentrations are limited to 1
and 25 ppm.
  The Agency does not intend to
determine compliance with this
provision by requiring that generators
actually monitor the concentration of
spent solvent in untreated wastewater.
Instead, the generator must be able to
demonstrate that the maximum amount
of solvents used during a week divided
by the average weekly flbwofjhe
influent into the headwprks of the final
wastewater treatment step would not
 22See footnotes 2 and 3.
 23 See footnote 21.
 exceed the standards established herein.
 This demonstration can be made
 through an audit of various records,
 already maintained at most faculties,
 including invoices showing solvent
 purchases, lists indicating to whom and
. how much solvent was .distributed, and
 other, similar, operatirig records.24 An
 EPA inspector would look to such
 documents to verify the computation
 made by the generator. The Agency is.
 selecting the average weekly influent
 flow, rather than a  system's, design flow,
 to take account of situations when the
 wastewater treatment system does not
 operate at design capacity; the
 treatment  system's headworks.is the
 appropriate part of the treatment facility
 on which to base average raw   ,
 wastewater influent concentrations,  '
 because final combination of different
 raw wastewater streams typically  takes
 place at that location!
   The following example shows how
 compliance could be demonstrated: If a
 facility estimates that it uses a
 maximum  of 700 kg of 1,1,1- .
 triohloroethane  (methyl chloroform,
 MG), and 150 kg of methylene chloride
 per week as solvents, and if the weekly
 flow into the headworks of the
 generator's wastewater treatment
 facility is estimated to average 5 MGD,
 the mixed wastewater would be exempt
 from the mixture rule-because the
 average MC concentration in its influent
 wastewater is 5.3 ppm,25 the average
 methylene  chloride  concentration is 1.1
 ppm, and the combined concentration is
 6.4 ppm, less than the exemption
 maximum of 25 ppm for the non-
 carcinogenic solvents.
   In using this means  of evaluating
 compliance, the  Agency is making a
 worst-case assumption that all solvent
 used at a facility becomes mixed with
 process wastewater, unless the facility
 can dempnstrate that a certain portion
 of the solvent is  not disposed to
 wastewater. This assumption is one of
 the factors the Agency believes justifies
 its decision to adopt'a concentration
 level for the spent solvents above
 health-based concentration values. The
 audit should be repeated whenever a
 change in the generator's operations
 could affect the amount of spent
 solvents in the wastewater.
   If EPA were to suspect a generator
  "However, if a facility can demonstrate by
means of appropriate records that any portion of
solvents used at the facility are not disposed to
wastewater, that portion is to be excluded from the
calculation. That portion of solvents which is .
volatilized may not be excluded from the
calculation of solvent usage.
  25 Calculated as follows: 700kg/wk x 1/7 wk/d x
1/5x10" d/gal x 1/3.8 gal/1 x 1 l/kg=5.3 ppm.
  was violating the provisions of this
  amendment, the Agency would follow
  normal investigatory steps (such as
  verifying supply records or interviewing
  employees) to ascertain the company's
  compliance. Deliberate falsification of
 • relevant records, of course, could .
  subject a generator to civil or criminal
  sanctions.    i     <

  B. Mixtures of Wastewater and
  Hazardous Wastes From Specific
  Sources Listed in 40 CFR 261.32

   The Agency believes that hazardous
 .wastes listed in §261.32 typically are
  generated in large volumes relative to
  the non-hazardous wastewaters      •
  generated at the same plant, and, if
  mixed with the wastewater, often
  constitute a significant portion of the
  wastewater mixture, thereby causing the
  mixture to pose a substantial hazard to
  human health or the environment. The
  Agency, therefore, believes that
  § 261.32-^-listed;wastes which are mixed
  with non-hazardous wastewater      •
  ordinarily shouM not be excluded from
  the mixture rule. However, the Agency
  will consider amending the mixture rule
  on a case-foy-case basis if a particular
  industry can provide sufficient evidence
  that their  §261.tt2—listed wastes* when
 mixed with their non-hazardous
 wastewater, would not present a
 substantial hazard. In fact, the petition
 processes established in § 260.20 can be
 used for this purpose.28
   At this time, in § 261.3(a)(2)(iv)(C) of
 today's amendment, the Agency has
 decided to grant API's request to    T"
 exclude from the mixture rule
 wastewater mixtures that are hazardous
 only because they contain EPA
 Hazardous Waste No. K050 (Heat
 exchanger bundle cleaning sludge from
 the petroleum refining industry) and
 which are treated in a facility subject to
 regulation under Section 402 or Section
 307(b). of the Clean Water Act. This
 listed hazardous waste  often is mixed
 with non-hazardous wastewater as a
- consequence  of backflushing of the heat
 exchanger bundles during intermittent
 cleaning operations in the course of
 refinery operations. Back-flushing is a
 daily routine maintenance procedure.
.More vigorous cleaning, often by •
 hydroblasting, is performed e,very one to
 two years. In .either case, the
 accumulated sludges are often disposed
  26For making such a demon;
 individual plant, the
 can be used.
      istration for an
•petition process under § 260.22

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56586
Federal Register / Vol.  46,  No. 221  / Tuesday, November 17, 1981  / Rules  and Regulations
to the refinery's sewer system. In two
large refineries, these sludges
correspond to 0.0004 percent and 0.002
percent of the wastewater flow into the
refineries treatment systems.27
  The heat exchanger bundle sludges
are listed as hazardous because they
contain hexavalent chrqmium. However,
data provided by API indicate that the
cleaning operations raise the total
chromium content of the raw
wastewater to much less than 1 ppm (24
to 63 ppb),28 a level unlikely to cause
harm, since it virtually meets the
National Interim Primary Drinking
Water Standard. The chromium also
would undoubtedly undergo further
attenuation before reaching
environmental receptors. In addition,
almost all of the chromium is reduced to
the trivalent state by reducing agents
such as sulfides present in the raw
wastewater. Refinery wastewater
(effluent from DAF float or API
separator) contains about 7.1 ppm of
sulfide, 0.7 ppm of trivalent chromium
and 0.02 ppm 6f hexavalent chromium.29
Two large refineries report 10-30 ppm of
sulfide in untreated wastewater.30
Although these wastes are alkaline
(pHB-9)" a condition conducive to the ,
oxidation of chromium, the tenfold
excess of sulfide is sufficient to reduce
the hexavalent chromium. Most of the
already small incremental increase of
chromium concentrations from this
source will therefore be in the relatively
non-toxic trivalent form.32 Although the
total environmental loading of       .
chromium in petroleum refinery
wastewaters resulting from heat
exchanger bundle cleaning sludges is
not inconsiderable (about 1300 kkg/
year),33 the fact that it is almost
completely trivalent, and is present in
low concentrations in those
wastewaters, justifies exempting them
from the mixture rule at 40 CFR
2G1.3(a)(2).
  >T toiler from S. M. D'Orsie, Exxon Company to
M Steinberg. Morgan, Lewis and Bockius, August
12. wai.
  **8«e footnote 3. These data were calculated from
Tables 111-5 and 111-10 of the referenced document.
  "See footnote 28,
  *&
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           Federal Register /  Vol. 46* No. 221  / Tuesday, November 17, 1981 /Rules  and Regulations    56S&7
 products (e. g., the discarding of § 261.33
 pesticides being used for pest control on
 the plarit property or the discarding of
 § 261.33 solvents or other materials used
 in plant maintenance). EPA believes that
 these discarded § 261.33 materials can
_ and should be segregated and
 separately managed as hazardous
 wastes. If they are intentionally or
 unintentionally mixed jvith non-
 hazardous; wastewaters, then suet
 waste-waters must managed  as
 hazardous wastes.           .

 D. Mixtures of Wasiewater and Wastes •
 Which Are Generated by Laboratory
 Operations   .•""-.
 .  In section 261.3(a)(2)(iv)(E) of today's
 amendment, EPA is exempting from the
 mixture" rule mixtures of non-hazardous
 wastewaters and laboratory           ,
. wastewaters that contain or may
 contain listed hazardous wastes,
 provided that the annual average,
 concentration of laboratory"
 wastewaters in the generator's total
 wastewater flow is less  than one
 percent. Most manufacturing plants -    -
 operate on-site laboratories either for
 the purpose of providing quality
 control3S or for performing research and
 development, or both. These    •
 laboratories typically .generate a variety
 of listed hazardous wastes including
 many of the spent solvents listed in
. § 261.31 and many materials listed in
 § 261.33.39 These laboratories may also
 discard samples or pprtions'of samples
 of listed hazardous wastes brought into
 the laboratory for analysis.     ,     ,
   Proper disposal of these hazardous
 wastes  and other laboratory wastes is a
 problem for all laboratories.  40~42
 Some of these .hazardous wastes are
 segregated and disposed of separately
 (e.g., by being sent to a landfill in
   3TWhere an unused material (such as toluene)
 which would be a listed spent solvent if discarded
 after use as a solvent, is instead discarded to
 wastewater prioi to use, the principle set out in this
 section applies, and the discharge does not count
 against the 1 or 25 ppm exclusion level for spent
 solvents mixed with wastewater. In this case, what
 is being discarded is not a spent solvent, but an
 unused commercial product or intermediate.
   38 This excluision covers laboratory wastes
 generated in the course of quality control
 measurements conducted near a unit operation, as
 well as analyses conducted in a formal laboratory
 setting. A pilot plant, however, is not considered to
 be a laboratory operation, because it is a scaled-
 down version of a manufacturing process, and so
 does not generate the diversity of chemical wastes
 which are characteristic of laboratory operations.
   39 A recent survey determined that more than 25
 different chemicals are used daily in 47 percent of
 1439 academic and industrial laboratories
 questioned, and that 100 different chemicals are •
 used daily in 30 percent of these laboratories.
 (Survey of Laboratory Practices and Policies for
'Employee Protection from Exposure to Chemicals).
 American Chemical Society, 115516th Street N.W.,
 Washington, D.C. 20036. July 1981.
 carefully packed "lab packs", or to an
 off-site or on-site incinerator). However,'
' a majority of these wastes are believed
 to be discharged through the
 laboratories'.sewers into the plants'
 wastewater collection and treatment
 systems. Indeed, some of these
 discharges are- almost unavoidable (e.g., •.
 laboratory spills washed into a sink
 drain, and residues from ^he washing  of
 glassware which are carried hi the
 washwater into the sewer). Other  _
 discharges are the most reasonable and
 efficient way of disposing of many of    '
 these wastes.
   The Agency believes that these
 discharges from laboratories into a
 plant's wastewater treatment system
 typically will be small relative to the
 total volume of the plant's wastewater.
 Moreover, the Agency believes that the
 concentration of listed hazardous   "
 wastes imparted to the plant's
.wastewaters by these laboratory
 discharges will be even smaller. API
 estimates 43 that refinery laboratories'
 discard to the wastewater sewer and
 treatment systems about 20 to 150 kg/
 month of various chemical wastes, some
 of which may be listed hazardous
 •wastes. Even if one assumes that all of
 these chemical wastes are listed
 hazardous wastes and are discharged
 into a typical daily wastewater flow of 5
 million gallons, the resulting
 concentration of listed hazardous       ;
 wastes in the wastewater would be 0.26
 ppm. The Agency believes that these
 concentrations, and even higher
 concentrations—up to 1 ppm—do not
 pose a substantial hazard to human
 health or the environment, even if these
 concentrations are  represented in
 wastewater discharges from the
 treatment systems (e.g., subsurface
 discharges from unlined surface
 impoundments).44
   To assure that the exemption in
 today's amendment is only available to
 highly diluted 4S mixtures of laboratory
 wastes and nonhazardous wastewaters,
   40 Survey of Laboratory Practices and Policies for
 Employee Protection from Exposure to Chemicals.
 American Chemical Society, 1155 18th Street NW.
 Washington, D.C. 20036. July 1981.
   41 Muir, G. D., Hazards in the Cheminal
 Laboratory. The Chemical Society, Burlington
 House, London WTVoBN. Second Edition, March
 1977.   •"  '           '         . '     :  ,
 •  42N. A. S. Prudent Practices for Handling
 Hazardous Chemicals in Laboratories. National
• Academy Press, Washington, D.C. 1981.
   43 See Footnote 2.
   "Moreover, the Agency believes that these
 concentrations in wastewaters will often be
 reduced by the physical, chemical or biological
 wastewater treatment processes typically
 employed.
   "For reasons of laboratory safety, it is standard
 operating procedure to discard laboratory wastes to
 the sewer system by admixture with copious
 amounts of water. See footnotes 40—12.
 EPA has incorporated a limit of one
 percent of 'laboratory wastewaters to
• total wastewater on an annual average
 volumetric basis. The limit is expressed
 in this way to simplify  the ,
 implementation of this  exemption, that
 is, to avoid  the necessity of sampling
 arid calculating or otherwise measuring
 or estimatirag the actual concentrations
 of listed hazardous wastes introduced
 by laboratories into wastewater sewer
 and treatment systems. .Under today's
 amendment, a generator may
 demonstrate compliance with this limit
 •by measuring (preferably) or
 conservatively calculating values of the
 annual average wastewater discharge
 from the laboratory and the  annual    .
: average wastewater flow entering the
 wastewater treatment system. EPA
 believes, that this limitation will
, typically assure laboratory-derived
 listed hazardous waste concentrations
 in wastewaters of less than 1 ppm,
 which the Agency deems will not pose a
 substantial  hazard to human health or
 the environment.      ,     >
   'It is possible that  some facilities,
. whose average laboratory wastewater '
 flow exceeds the exemption limit of one
 percent of ihe total wastewater flow, do
 not discharge hazardous chemical
 wastes into their wastewaters in
 amounts warranting application of the
 mixture rule. The Agency has therefore
 provided another compliance test, which
 some facilities may prefer to employ;
.facilities may be able to show that the
 estimated combined average
 concentration of toxic (T) §§261.31,
 261.32 and 261.33 materials resulting
 from laboratory operations; in the
 headworks  of their wastewater .
 treatment system does not exceed 1
 ppm.46 If choosing this option, a facility
 will be able to show compliance by
 means of ail audit of laboratory
 purchases, an estimate  of the aggregate
 amounts of  § § 261.31, 261.32  and 261.33
 toxic materials utilized, and  data'on
 wastewater flow into the headworks of
 its treatment or pre-treatment facility.
 Facilities must make the worst case
   46 For the purpose of rendering regulatory
 compliance less burdensome the Agency has chosen
 to set a single Ilimlt for all hazardous laboratory
 wastes. The limit was set at 1 ppm of toxic (T) listed
 wastes because laboratories .work with a wide mix
 of chemicals (see footnote 39), and an appreciable
 fraction of thesie chemicals are carcinogens: 5% of
 the laboratories surveyed use more than 250 gm of
 OSHA-regulated carcinogens daily, weekly 9r
 monthly (see document referred to in footnote 41).
 As a point of clarification: listed wastes which are
 hazardous solely because they exhibit one or more
 of the characteristics of hazardous waste identified
 in Subpart C ol: Part 261 are riot included in this
 calculation. (See discussion in the text at ill above).
 The regulatory language in § 261.2(a)(v)(E) reflects
 this point.    j      '-'-•-     '  *         .  .

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 56588    Federal Register  /  Vol. 46,  No. 221  /  Tuesday, November 17, 1981 /  Rules and Regulations
 assumption that all listed hazardous
 wastes used in the laboratories will be
 discarded to wastewater, unless they
 can demonstrate through appropriate
 records that these materials were
 disposed of elsewhere. The data should
 be averaged on a yearly basis (an
 annualizcd basis was chosen in order to
 even out fluctuations, and in order to
 simplify recordkeeping).

 III. Wastes Listed Solely Because They
 Exhibit a  Hazardous Waste
 Characteristic
   Certain wastes are listed in §§261.31,
 261.32 and 261.33 solely because they
 exhibit one of the characteristics of
 hazardous waste. Examples are
 hazardous wastes F003 (certain ignitafale
 solvents), K044.  K045 and K047 (certain
 residues from explosives manufacture),
 and certain discarded commercial
 chemicals listed in § 261.33 (e)  and (f).
 Mixtures of any of these wastes and
 other solid wastes are presumptively
 hazardous by application of the mixture
 rule. This result  seems inappropriate,
 because the mixture itself can be tested
 to determine whether it exhibits the
 characteristics of hazardous wastes.
 Therefore, in § 261.3(a)(2)(iii) of today's
 amendment, EPA is exempting from the
 mixture rule mixtures of non-hazardous
 solid wastes and wastes listed in
 subpart D solely because they exhibit
 one or more of the hazardous waste
 characteristics identified in Subpart C.
 Tills amendment, unlike the others
 adopted today, applies to all waste
 mixtures, not Just to mixtures of listed
 wastes and wastewaters whose
 discharge is subject to regulation under '
 section 402 or 307(b) of the Clean Water
 Act.

 IV. Effective Date
  Section  3010(b) of RCRA provides that
 EPA's hazardous waste regulations and
 revisions to the regulations  take effect
 six months after promulgation. The
 purpose of this requirement is to allow
 persons handling hazardous waste
 sufficient lead time to prepare and to
 comply with major new regulatory
 requirements. For the amendment
 promulgated today, however, the
 Agency believes that an effective date
 of six months after promulgation would
 cause unnecessary disruption in the
 implementation of the regulation and
 would not be in the public interest.
 Since this  amendment reduces, rather
 than increases, the existing
 requirements for persons generating
hazardous waste, there is no basis for
allowing a lengthy period of time for
persons managing treatment facilities, to
prepare for compliance. Therefore, this
  amendment will take effect immediately
  as an interim final rule.
  V. Interim Final Rule and Request for
  Comment
    EPA has determined under section 553
  of the Administrative Procedure Act, 4
  U.S.C. 553, that there is good cause for
  promulgating these amendments as
  interim final rules without prior notice
  and comment. In the first place, the
  Agency during the comment period on
  the May 19 regulations, already .has
  received comments criticizing the
  applicability of the mixture of certain
  discarded process wastes and process
  wastewaters. Today's action is a direct
  outgrowth of these comments. The
  Agency thus believes that the policy
  underlying the notice and comment
  requirement has been substantially
  satisfied here. EPA further believes that
  the effect of delaying promulgation of •
  this amendment would be disruptive
  and counterproductive and could cause
  unnecessary hardship to many facilities.
'  We are particularly concerned that
  facilities which otherwise would not be
  deemed to be managing hazardous
  wastes might have to install.
  groundwater monitoring wells at
  substantial expense because their
  wastewater is presumptively hazardous.
  Since the groundwater monitoring
  requirement becomes effective on
  November 19,1981, the present
  amendment, as a practical matter, must
  be implemented immediately to provide
  relief to this class of facilities. In this
  situation, we. think the use of advance
  notice and comment procedures would
  be contrary to the public interest.
   At the same time, the Agency believes
  that the public should have an
  opportunity to comment on this rule,
  and, indeed, specifically invites
  comment on the issues raised herein.
 Thus, readers will have ample
  opportunity to comment before these
  amendments are issued in "final final"
 form.                        .

 VI. Regulatory Impact

   Under Executive Order 12291,  EPA
 must judge whether a regulation is
 "major" and therefore subject to the
 requirement of a Regulatory Impact
 Analysis. This interim final regulation is
 not a major rule because it will not
 result in an effect on the economy of
 $100 million or more, nor will it result in
 an increase in costs or prices to
 industry. In fact, this regulation will
 reduce the overall costs and economic
 impact of EPA's hazardous waste
 management regulations. There will be
 no adverse impact on the ability of U.S.-
 based enterprises to compete with the
 foreign-based enterprises in domestic or
  export markets. Because this
  amendment is not a major regulation, no
  Regulatory Impact Analysis is being
  conducted.
    This amendment was submitted to the
  Office of Management and Budget
  (OMB) for review as required by
  Executive Order 12291.

  VII. Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility
  Act, 5 U.S.C. 601 et seq., whenever an
  agency is required to publish general
  notice of rulemaking for any proposed or
  final rule, it must prepare and make
  available for public comment a
 "regulatory flexibility analysis which
  describes the impact of the rule on small.
  entities (Le., small business, small
  organizations, and small governmental
  jurisdiction). The Administrator may
 •certify, however, that the rule will not
  have a significant economic impact on a
  substantial number of small entities.
   This amendment will generally have
  no adverse economic impact on small
  entities. Accordingly, I hereby certify
  that this 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.
   Dated: November 12,1981,
  Anne M. Gorsuch,
 Administrator.'

  PART 261—IDENTIFICATION AND
.  LISTING OF HAZARDOUS WASTE

   Forthe reasons set out in the
 preamble, 40 CFR Part 261 is amended
 as follows!
   1. The authority citation fpr Part 261
 reads 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, 6921, and 6922].  .

   2. In § 261.3, paragraph (a)(2) is
 revised to read as follows:

 §26t.3  Definition of hazardous waste.
   (a) * * *
   (2) It meets any of the following
 criteria:      f
   (i) It exhibits any of the
 characteristics of hazardous waste
 identified in Subpart C.                .,
   (ii) It is listed in Subpart D and has
 not been excluded from the lists in
 Subpart D under §§260.20 and 260.22 of
 this chapter.
   (iii) It is a mixture of a  solid waste
 and a hazardous waste that is listed in
 Subpart D solely because it exhibits one
 or more of the characteristics of
 hazardous waste identified in Subpart

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Federal Register / Vol. 46, No.  221 //Tuesday.
                                                                                               Re8ulat°nS
 C, unless the resultant mixture no longer
 exhibits any characteristic of hazardous
 waste identified in Subpart'C?
   (iy) It is a mixture of solid waste and
 one or more hazardous wastes listed in
 Subpart D and hasd not been excluded
 from this paragraph under §§260.20 and
 260.22 of this chapter; however, the
 following mixtures of solid wastes and
 hazardous wastes listed in Subpart D  .
 are not hazardous wastes [except by
 application of paragraph (a)(2) (i) or (ii)
 of this Section) if the generator can
 demonstrate that the mixture consists of
 wastew'ater the discharge of which is
 subject to regulation under either
 Section 402 or Section 307(b) of the
 Clean Water Act (including wastewater
 at facilities which have eliminated the
 discharge of wastewater) and:
   (A) One or more of the following spent
 solvents listed in § 261.31—carbon --..
 tetracMoride.'tetrachloroethylene,
• trichbroethylene—provided that the
 maximum total weekly usage bf these
 solvents [other than the amounts that
 can be demonstrated not to be        • ,
 discharged to wastewater) divided* by
 the average weekly flow o'f wastewater
/ into the headworks of the facility's
 wastewater treatment or pre-beatment
 system does not exceed 1 part per,
 million; or          ,     ;
   (B) One or more of the following spent
solvents listed in § 261.31—methylene
chloride, 1,1,1-trichloroethane,
chlorobehzene, q-dichlorobenzene,
cresols, cresylic,acid, nitrobenzene,
toluene, methyl ethyl ketone, carbon
disulfide, isobutanol, pyridine, spent ,
chlorofluorocarbon solvents—-provided
that the maximum total weekly usage of
these solvents (other than the amounts
that can be demonstratedjiot to be
discharged to wastewater) divided by
the average weekly flow of wastewater
into the headworks of the facility's
wastewater treatment or pre-treatment
system does not exceed 25 parts per
:.million; or
   (C) One of the following wastes listed
in § 261".32—heat exchanger bundle
cleaning sludge from the petroleum '
refining industry (EPA Hazardous
Waste No. K050); or   ;
   (D) A discarded commercial chemical
product, or chemical intermediate listed
in § 261.33, arising from de minimi's '
losses of these materials from
manufacturing operations in which these
materials are used as raw materials or
are produced in the manufacturing
process. For purposes of this sub-
paragraph, "de minimi's" losses include
those from normal material handling
operations (e.g. spills from  the unloading
or transfer of materials  from bins or
.other containers, leaks from pipes,
                                                                     valves or other devices used to transfer •
                                                                     materials); minor leaks of process
                                                                     equipment, storage tanks or containers;
                                                                     leaks from well-maintained pump
                                                                     packings and seals; sample purgings;
                                                                     relief device-discharges; discharges from
                                                                     safety showers and rinsing and cleaning
                                                                     of personal safety equipment; and
                                                                     rinsate from empty containers or from
                                                                     containers that are rendered empty by
                                                                     that rinsing; or
                                                                       (E) Wastewater resulting-from
                                                                     laboratory .operations containing toxic
                                                                     (T) waste? liisted in Subpart D, provided
                                                                     that the annualized average flow of  : \;
                                                                     laboratory wastewater does not exceed
                                                                     one percent 6f total wastewater flow iv
                                                                     into .thei headworks of'the facility's
                                                                     wastewater 'treatment or pre-treatment
                                                                     system, or provided the wastes,     •
                                                                     combined atiinualized average      ,
                                                                     concentration does not exceed one part
                                                                     per million in the headworks of the   ,
                                                                     facility's wastewater treatment or pre-
                                                                     treatmentfaicih'ty. Toxic (T) wastes used
                                                                     in laboratories that are demonstrated .
                                                                     not to be discharged to wastewater are
                                                                     not to be included in this calculation.'
                                                                     JFR Doo. 81-33191 Filed li-lft-Sl; 8:45 am]
                                                                      BILLING CODE 6! 60-30-M

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