PA
                 United States
                 Environmental Protection
                 Agency
              OH.ce of
              Solid Waste ana
              Emergency Response
DIRECTIVE NUMBER: 9441.37(84)

TITLE:  Clarification of Policy on Hazardous Waste Derived
      from Mixture of Leachate and Precipitation Run-Off
      at Landfills, Waste Piles and Land Treatment Units

APPROVAL DATE:  n-14-84

EFFECTIVE DATE:  ii-u-84

ORIGINATING OFFICE:  office of solid Waste

E FINAL

D DRAFT

  LEVEL OF DRAFT

    DA — Signed by AA or OAA
    D B — Signed by Office Director
    DC — Review & Comment

REFERENCE (other documents):
  OS WER       OS WER       OS WER
VE    DIRECTIVE    DIRECTIVE    Dl

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PART 261  SUBPART A- GENERAL                                 DOC:  9441.37(84)


Key Words:    Mixture Rule

Regulations:  40 CFR 261,3(a)(2)(iii,iv), 261.3(b)(2), 261.3(c)(2); 264 and 265

Subject:      Clarification of Policy on Hazardous Waste Derived from Mixture
              of Leachate and Precipitation Run-Off at Landfills, Waste Piles
              and Land Treatment Units

Addressee:    Hazardous Waste Division Directors, Regions I-X

Originator:   John Skinner, Director, Office of Solid Waste

Source Doc:   #9441.37(84)

Date:         11-14-84

Summary:

     Precipitation run-off is not presumed to be a hazardous waste under
§261.3(c)(2).   In contrast, leachate from the treatment, storage, or disposal
of a hazardous waste is itself a hazardous waste by definition [§261.3(c)(2)].
Precipitation  run-off is considered a hazardous waste under the following
conditions:  it is mixed with a listed hazardous waste or leachate (unless
the mixture is delisted), or it is mixed wiht a characteristic hazardous
waste (unless  it-is shown not to exhibit any hazardous characateristics)
[§261.3(a)(2)(iii), (iv), and (b)(2)].

     Run-off from the active portions of hazardous waste landfills and waste
piles, because of unit design, will almost inevitably consist in part of leachate
and should be  considered a hazardous waste unless the owner/operator can
demonstrate that it consists only of precipitation run-off.  Run-off from
closed portions of these units usually has not had the opportunity to mix with
leachate and therefore can generally be presumed not to be hazardous.

     The Agency will not presume that collected run-off from a typical land
treatment unit is a hazardous waste.  However, the owner or operator of active
and inactive units must still collect all run-off in accordance with the Part
264 and 265 regulations and determine whether the run-off exhibits any of the
characteristics of a hazardous waste defined in Subpart C of Part 261.

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                                                               9441.37 (84)
       Management of Precipitation Run-off from Land Treatment Units


       John H. Skinner, Director
       Office of Solid Waste  (WH-562)

       Hazardous Waste Division Directors/
       Regions I-X

       INTRODUCTION

            In the attached April 10, 1984 memo addressed to David
       Wagoner of Region VII, I described OSW's policy on the management
       of precipitation run-off from active, inactive, and closed portions
       of hazardous waste management units.  The April 10 memo focussed
       primarily on scenarios applicable to waste piles and landfills.
       This memo clarifies some of the important concepts discussed in
       the April 10 memo and describes how OSWs policy on management of
       run-off applies to hazardous waste land treatment units.

S      SUMMARY
\
CO
^           Under 40 CFR 261.3(c)(2), precipitation run-off is not
r-i      presumed to be a hazardous waste.  In contrast, leachate generated
7!      from the treatment, storage, or disposal of a hazardous waste
•5      is a hazardous waste by definition (§261.3(c) (2)).  A mixture
2      of precipitation run-off with a listed hazardous waste is a
™      hazardous waste unless the mixture is delisted, and a mixture of
°      precipitation run-off with a characteristic hazardous wast*e is

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      In  all cases,  the owner or  operator must  still collect all
 run-off  in accordance with  the Part- 264 and 265 regulations and
 is  still responsible for determining whether the run-off exhibits
 any of the characteristics  of a  hazardous waste defined in Subpart
 C'of  Part 261.

 DISCUSSION

 Clarification of April 10 memo

      My April 10 nemo explained  the  key definitions and concepts
 regarding the management of run-off  from land-based hazardous
 waste treatment, storage, and disposal units.  In understanding
 that  policy, it is  important to  recognize the  relationship between
 leachate and run-off, and the applicability of the mixture rule
 (5261.3(a)(2)(iii)  and ( iv) and  261.3(b}(2)) and the "derived
 from" rule (S261.3(c) (2) ) .

      ° Precipitation 'Run-off

      "Run-off" i's defined in S260.10 as "any rainwater, leachate,
 or  other liquid that drains over land from any part of a facility."
 Run-off generally consists  of precipitation (rainwater) run-off,
 and may also contain leachate.   EPA  intends "run-off" to cover
 liguid that flows over and  quickly off of the  land surface of the
 facility.  Because  of this, any  contact bqj/een precipitation
 run-off and waste will fn*t  be minimal. In the preamble to the
 regulations issued  on May 19, 1980  (45 FR 33096), EPA expressed
 this by stating:  "... the  water in  precipitation run-off in many
 cases may not have  had sufficient contact with the waste to
 solubilize waste constituents."  Because of the belief that in '
many cases run-off  would contain neither leachate nor significant
 levels of waste constituents, EPA did not categorically list
run-off as a hazardous waste and because of the lack of significant
contact between precipitation run-off and leachate, EPA specifically
excluded precipitation run-off from  the "derived from" rule in
§261.3(c)(2).

     There are two  situations, however, in which EPA classifies
run-off as a hazardous waste.   First, it is a hazardous waste if
it exhibits any of  the characteristics of a hazardous waste
defined in Subpart C of Part 261.  Second, under the mixture rule
 ($261.3(a)(2)(iii) and (iv)),  it is a hazardous waste if it is
mixed with a hazardous waste,  including leachate.   Regardless of
whether the run-off is judged to be hazardous or nonhazardous, it
still must be collected in  accordance with the Part 265 and 264
regulations.
     "Leachate" is defined in $260.10 as "any liquid, including
any suspended components in the liguid, that has percolated
through or drained from a hazardous waste."  EPA intends that

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"leachate" broadly refer to any liquid that has made significant
contact with a hazardous waste by draining from it or passing
through it.  Although leachate varies in quality, it typically
contains significant levels of solubilized waste constituents.
EPA is particularly concerned about liquid that has passed
downward through the wastes in the waste management unit and
emerges from the bottom or side of the unit.

     Under the "derived from" rule, leachate from a hazardous
waste is defined as a hazardous waste.  Leachate derived from a
listed hazardous waste is considered a listed hazardous waste,
and it must be handled as such unless (1) it is delisted pursuant
to 40 CFR 260.20 and 260.22, or (2) in the case of the few
listed wastes listed soley because they failed a characteristic
of Part 261, Subpart C, it no longer noets the characteristic
(5261.3 (a)(2) (iii)).  Leachate derived from characteristic
wastes is presumed to be a hazardous waste until it is shown
that the leachate does not exhibit any of the characteristics
of a hazardous waste defined in Subpart C of Part 261.

     ° Mixture of Precipitation Run-off and Leachate

     The mixture rule in §261.3(a)(2)(iv) states that a solid
waste is a hazardous waste if it is a mixture of solid waste
and one or more hazardous wastes listed in Subpart D.  [Waste
mixtures containing characteristic hazardous wastes are treated
just like any other solid waste, i.e., they will be considered
hazardous only if they meet the characteristics.]

     The mixture rule applies to precipitation run-off (and
indeed any other solid, nonhazardous waste or material that
is mixed with a listed hazardous waste).  Because leachate
from hazardous waste is named as a hazardous waste under
§261.3 (c)(2), a mixture of precipitation run-off and leachate
is a hazardous waste.  The key factor in determining whether
precipitation run-off has mixed with leachate is the unit
design.  The evaluator must determine if the design allows
leachate to migrate from the bottom or side of the unit and
mix with precipitation run-off in a common collection facility.
Figure 1 in the appendix to my April 10 memo illustrates a
typical landfill scenario in which leachate and precipitation
run-off mix.  In this scenario, leachate percolates downward
through the waste and then moves laterally along an underlying
intermediate cover.  This leachate then seeps from the active
face and accumulates in the same areas as the precipitation
run-off from the active area.-

     Because of the usual design of landfills and waste piles,
it is highly likely that in the active portions of these units
the run-off and leachate will mix. (An exception would be a
pile or landfill operated under a roof).  Because Parts 264 and
265 require'collection of the run-off, the collection unit will

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 likely  contain  a mixture  of  precipitation  run-off  and" leachate.
 Due  to  the mixture  rule,  this  run-off  will likely  be  a  hazardous
 waste.

      Because  the generation  of leachate  is minimized  in
 properly  closed portions  of  these  units, it is nuch less  likely
 that leachate and run-off will commingle in properly  closed
 and  maintained  portions.   This run-off/  therefore, is usually
 not  a hazardous waste because  it is  unlikely that  the precipitation
 run-off has mixed with-  leachate.

 Policy  for Land Treatment Units

      My April 10 memo did not  specifically describe how the
 above policy  is applied to hazardous waste land treatment units.
 ffowever,  references to  land  treatment  units were made in  the
 appendix  to the memo.   Several of  these references need further
 clarification,  mialeadirn'j.  These references suggested that the
 run-off from  active and closed portions of these units  should be
 presumed  to he  a hazardous waste because the run-off  would in most
 cases come into contact with surface-applied wastes.
              0
      The  regulations and  preamble  discussion on run-off from
 hazardous waste land treatment units do not specifically address
 whether precipitation run-off  and  leachate will usually mix
 in the  active or closed portions of these  units.  To  clarify,
 the  Agency will not initially  presume  that this mixture will
 occur in  the  active or closed  portions of  typical land  treatment
 units.  Therefore, run-off from these  units will generally not be
 considered a  hazardous waste (unless it exhibits a characteristic).
 The  following discussion  explains  the  basis  for and possible
 exceptions to this general policy.

      The  same general concepts  described above for landfills and
 waste piles apply to land  treatment units.    First, the  "derived
 from" rule does not apply  to precipitation  run-off (i.e., unlike
 leachate  from a hazardous  waste, precipitation run-off  is not
 presumed  to be  a hazardous waste).  Limited contact of precipitation
 run-off with  the waste on  the  soil surface  does not automatically
 render  the run-off a hazardous  waste.  Second, run-off  is a
 hazardous waste if it (1)  exhibits any of  the characteristics of
 a hazardous waste, or*(2)  mixes with a listed hazardous waste or
 leachate.   Third,  the most important factor in determining whether
 run-off and leachate have mixed is the design of the  unit.

      The design of land treatment units is fundamentally different
 from  landfills a^d waste piles.  Land  treatment units rely on
 successful treatment rather  than physical barriers to prevent
escape of waste components.  They are  "open systems"   in that
 they  are not required to have  liners for containing waste.  At a
 typical land  treatment unit,  wastes are treated in the treatment
 zone  and treated soil pore liguid  (or  "leachate")* is then allowed
 to move out of the bottom of the unit  (see Figure 1 in attachment

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2).  The absence of restrictive layers in the treatment zone of
a land treatment unit, such as intermediate covers for lifts in
a landfill, limits the lateral movement of "leachate."  Also, most
land treatment units are relatively flat, which decreases the
chance for "leachate" seeps out side slopes should any lateral
movement occur.  Because of this desiqn, it is unlikely that
"leachate" will move laterally and mix with run-off from active or
closed portions of typical land treatment units.  Therefore, the
run-off from typical 1'and treatment units will not be oresumecf to be
a hazardous waste.  The issue of "soil pore liquid" versus "loachate"
(see footnote) does not affect the run-off policy for this case.

     There are certain land treatment unit designs that
may allow the mixing of "leachate" with run-off, and for which the
run-off policy is still unclear.  For example, certain units may
be designed to include a liner system that promotes the lateral
movement and commingling of "leachate" and run-off.  Figure 2
in attachment 2 illustrates this case.  Another example is whore
the ground water at least periodically discharges to a run-off
collection ditch or impoundment, e.g., where the run-off collection
ditch or impoundment is constructed below the water table and
downqradient of the facility.  In this case, "leachate" and
run-off would mix, as illustrated in Figure 3 of attachment 2.
The runrpff policy for these two cases (i.e., figures 2 & 3), as
well as^esiqns that may be used to lower the water table (e.g.,
drainage systems), is dependent on the resolution of the leachate/
soil pore liquid issue.  When we complete the evaluation of this
issue, additional guidance addressing these cases will be provided.
      petitioners in the Part 264 regulation litigation recently
questioned whether treated soil pore liquid should be considered
"leachate."  It may be argued, for example, that soil pore
should no longer b« hazardous alter it is "treated" anO e
from the bottom.of the treatment Ton« «* «t rro>jiiv ^-pratina land
tr«atr»ent unit.  If auch liquid is deemed to bo "leachate", any
around water or other liquid with which the leachate mixes would
also be a hazardous waste.  Thus, any ground water withdrawn to
artificially lo^pr tho water table (to comply with-tho one meter
separation requirement under £264.271) would have to be managed as
a hazardous waste.  OSM is currently evaluating this issue, and
its ramifications on LT unit designs, particularly in high water
table areas.  Additional guidance will be provided on this issue
when this evaluation id completed.

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     Please contact Ken Shuster, Chief of the Land Disposal
Branch, at FTS 382-3345, or Art Day at 332-4680 if you have any
questions or additional information is needed.

Attachments

cc:  John Lehman
     Eileen Claussen
     Bruce Weddle
     Dov Weitraan
     Nancy Hutzel

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          UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                     WASHINGTON. D.C. 20460
                                2fl .„,	                 OFPICEOP
                                U  J."."        SOLID WASTE AND EMERGENCY RESPONSE

MEMORANDUM                            OSWER Directive I 9450.6-1A


SUBJECT:  RCRA Exclusions Under Section 3001(b)(2)(A) of RCRA
          as Applied to Hydrogen Sulfide Scrubber  Wastes from
          Geothermal Power Plants

FROM:     Marcia Williams, Director (WH
          Office of Solid Waste

TO:       Harry Seraydarian, Director
          Toxics and Waste Management Division  (T-l)
          Region IX


     In your memorandum of September 20, 1985,  you ask whether
the RCRA exclusion under 40 CFR $261.4(b)(5) applies to
hydrogen sulfide scrubber wastes generated after the production
of electricity at geothermal power plants.  You note that the
process of converting geothermal energy (steam) to electricity
involves the generation of condensate as a waste product.  The
scrubber wastes are generated by scrubber systems  which are used
to remove sulfides from the condensate.

     The geothermal facilities claim that these wastes are exempt
from hazardous waste regulation under 40 CFR $261.4(b)(5) which
excluded  "drilling fluids, produced waters, and other wastes
associated with the exploration, development, or production of
crude oil, natural gas or geothermal energy."   You are proceeding
with the preparation of enforcement actions against the land
disposal facilities receiving the hydrogen sulfide wastes and
seek assurance that the wastes are not covered by  the exclusion.
The scope of the regulatory exclusion in 5261.4(b)(5) is determined
by the scope of the exclusion in Section 3001(b)(2)(A) of RCRA.

     The key interpretative language for the "drilling fluid"
exclusion is found in the legislative history (Solid Waste Disposal
Act Amendments, Conference Report, H.R. Rep. No. 1444, 96th Cong.,
2d Sess. 32 (1980)):

     The term "other wastes associated" is specifically
     included to designate waste materials intrinsically
     derived from the primary field operations  associated

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     with the explorationf development, or production of
     crude oil, natural gas or geothermal energy.  It
     would cover such substances as:  hydrocarbon bearing
     soil in and around related facilities; drill cuttings;
     materials (such as hydrocarbon, water, sand, and
     emulsion) produced from a well in conjunction with
     crude oil, natural gas or geothermal energy; and the
     accumulated material (such as hydrocarbon, water, sand,
     and emulsion) from production separators, fluid treating
     vessels, storage vessels, and production impoundments.

     The phrase "intrinsically derived from the primary
     field operations ..." is intended to differentiate
     exploration, development, and production operations
     from transportation (from the point of custody transfer
     or of production separation and dehydration) and
     manufacturing operations.

     Based on the facts you present, we agree that hydrogen sulfide
scrubber wastes are not within the Section 3001(b)(2)(A) exclusion
and, therefore, are subject to the hazardous waste regulations.
However, our conclusion is based on legal considerations which are
different from those cited in your memorandum.

     The key statutory references to "exploration, development,
or production" refer to locating energy deposits and extracting
the oil, gas, or geothermal energy (steam) from those deposits.
The two wastes listed in the statute also relate to the extraction
of oil, gas, or geothermal energy:  "drilling fluids" are used to
aid in oil, gas, and geothermal extraction, while "produced waters"
are extracted from the ground together with oil and gas.  The
legislative history cited above supports the view that "other
wastes" should also be limited to wastes relating to the extraction
process, and should not be extended to include later processing
or ir.a:;ufacturir.g operations.

     As the language and legislative history of Section
3001(b)(2)(A) make clear, only wastes "intrinsically derived
from primary field operations," i.e., derived from the process of
extracting th« geothermal steam itself, are covered by the
exclusion.  The scrubber wastes are not covered by the exclusion
because these wastes result not from the physical extraction of
the geothermal energy, but from a separate manufacturing process
downstream from the production operations.  The generation of
electricity is a separate process because it uses the steam as
fuel to drive turbines and generate electricity.

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     Hence, the considerations discussed in your memorandum are
not directly relevant to the determination that scrubber wastes
are not covered by the exclusion.  Our decision does not depend
upon whether the scrubber systems are essential or unique to
the production of electricity.  Additionally, the fact that the
scrubbers add constituents to the treatment sludge is not
necessarily determinative.  The crucial consideration is that
the generation of electricity is a type of operation that goes
beyond the statutory scope of the exclusion.  The statutory
scope is limited to the "production" of geothermal energy itself
and does not extend to subsequent uses of that geothermal energy
in power plants or other industrial operations.  Therefore, if
the hydrogen sulfide scrubber wastes are hazardous, they should
be regulated and managed in compliance with Subtitle C of RCRA.

cc:  All Regional Waste Management
       Division Directors
     Margie Russell

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