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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