United States
                             Environmental  Protection
 Office of
 Solid Waste and
 Emergency Response
Directive No. 9355.0-49FS
EPA  540-F-93-035
PB 93-963339
September 1993
                             Presumptive   Remedy  for
                             CERCLA  Municipal  Landfill
Office of Emergency and Remedial Response
Hazardous Site Control Division 5203G
                            Quick Reference Fact Sheet
      Since Superfund's inception in 1980, the remedial and removal programs have found that certain categories of sites have
      similar characteristics, such as types of contaminants present, types of disposal practices, or how environmental media
      are affected. Based on information acquired from evaluating and cleaning up these sites, the Superfund program is
      undertaking an initiative to develop presumptive remedies to accelerate future cleanups at these types of sites. The
      presumptive remedy approach is one tool of acceleration within the Superfund Accelerated Cleanup Model (SACM).

      Presumptive remedies are preferred technologies for common categories of sites, based on historical patterns of remedy
      selection and EPA's scientific and engineering evaluation of performance data on technology implementation. The
      objective of the presumptive remedies initiative is to use the program's past experience to streamline site investigation
      and speed up selection of cleanup actions. Over time presumptive remedies are expected to ensure consistency in remedy
      selection and reduce the cost and time required to clean up similar types of sites. Presumptive remedies are expected to
      be used at all appropriate sites except under unusual site-specific circumstances.

      This directive establishes containment as the presumptive remedy  for CERCLA municipal landfills.  The framework for
      the presumptive remedy for these sites is presented in a streamlining manual entitled Conducting Remedial Investiga-
      tions/Feasibility Studies for CERCLA Municipal Landfill Sites, February 1991 (OSWER Directive 9355. 3-11). This
      directive highlights and emphasizes the importance of certain streamlining principles  related to the  scoping (planning)
      stages of the remedial investigation/feasibility study (RI/FS) that were identified in the manual.  The directive also
      provides clarification of and additional guidance in the following areas: (1) the level of detail appropriate for risk
      assessment of source areas at municipal landfills and (2) the characterization of hot spots.

      Superfund has conducted pilot projects at four municipal
      landfill sites1 on the National Priorities List (NPL) to
      evaluate the effectiveness of the manual Conducting
      Remedial Investigations/Feasibility Studies for CERCLA
      Municipal Landfill Sites  (hereafter referred to as "the
      manual") as a streamlining tool and as the framework for
      the municipal landfill presumptive remedy. Consistent
      with the National Oil and Hazardous Substances Pollution
      Contingency Plan (or NCP), EPA's expectation was that
      containment technologies generally would be appropriate
      for municipal landfill waste because the volume and
      heterogeneity of the waste generally make treatment
      impracticable. The results of the pilots support this
      expectation and demonstrate that the manual is an
      effective tool for streamlining the RI/FS process for
      municipal landfills.
 Since the manual's development, the expectation to
 contain wastes at municipal landfills has evolved into a
 presumptive remedy for these sites.'Implementation of
 the streamlining principles outlined in the manual at the
 four pilot sites helped to highlight issues requiring
 further clarification, such as the degree to which risk
 assessments can be streamlined for source areas and the
 characterization and remediation of hot spots.  The
 pilots  also demonstrated the value of focusing
 streamlining efforts at the scoping stage, recognizing
 that the biggest savings in time and money can be
 realized if streamlining is incorporated at the beginning
 of the RI/FS  process. Accordingly, this directive
 addresses those issues identified during the pilots and
 highlights streamlining opportunities to be considered
 during  the  scoping component of the RI/FS.
      1 Municipal landfill sites typically contain a combination of principally
      municipal and to a lesser extent hazardous wastes.
2See EPA Publication 9203.1-021, SACM Bulletins, Presumptive
Remedies for Municipal Landfill Sites, April 1992, Vol. 1, No. 1, and
February 1993, Vol. 2, No. 1, and SACM Bulletin Presumptive
Remedies, August 1992, Vol. 1, No. 3.

Finally, while the primary focus of the municipal landfill
manual is on streamlining the RI/FS, Superfund's goal
under SACM is to accelerate the entire clean-up process.
Other guidance issued under the municipal landfill
presumptive remedy initiative identifies design data that
may be collected during the RI/FS to streamline the
overall response process for these sites (see Publication
No. 9355.3-18FS, Presumptive Remedies: CERCLA
Landfill Caps Data Collection Guide, to be published in
October 1993).


Section 300.430(a)(iii)(B) of the NCP contains the
expectation  that engineering controls,  such  as
containment, will be used for waste that poses a relatively
low long-term  threat  where treatment is impracticable.
The preamble to the NCP identifies municipal landfills
as a type of site where treatment of the waste may  be
impracticable because of the size and heterogeneity of
the contents (55 FR 8704). Waste in CERCLA landfills
usually is present in large volumes and is a heterogeneous
mixture  of municipal waste frequently co-disposed
with industrial and/or  hazardous waste.  Because
treatment usually is impracticable,  EPA generally
considers containment to be the appropriate response
action, or the "presumptive remedy," for the source
areas of municipal landfill sites.

The presumptive remedy for CERCLA municipal
landfill sites relates  primarily to containment of the
landfill mass and collection and/or treatment of landfill
gas. In addition, measures to control landfill leachate,
affected  ground water at the perimeter of the landfill,
and/or upgradient ground-water  that  is causing  saturation
of the landfill mass may  be implemented as part of the
presumptive remedy.

The presumptive remedy does  not address  exposure
pathways outside the source area (landfill), nor does it
include the long-term ground-water response action.
Additional RI/FS activities, including a risk assessment,
will need to be performed, as appropriate, to address
those exposure pathways outside the source  area. It is
expected that RI/FS activities addressing exposure
pathways outside the  source generally will reconducted
concurrently with the streamlined RI/FS for the landfill
source presumptive remedy. A response action for
exposure pathways outside the source (if any) may be
selected together with the presumptive remedy (thereby
developing a comprehensive site response), or as an
operable unit separate from the presumptive remedy.

Highlight  1 identifies  the  components of the presumptive
remedy.  Response actions selected for individual sites
will include only those components that are necessary,
based on site-specific conditions.
     Highlight 1:  Components of
     the Presumptive Remedy:
     Source Containment
          Landfill cap;

          Source area ground-water control
          to contain plume;

          Leachate collection  and treatment;

          Landfill  gas  collection  and
          treatment; and/or
          Institutional controls to supplement
          engineering controls.
The EPA (or State) site manager will make the initial
decision of whether a particular municipal landfill site
is suitable for the presumptive remedy or whether a
more comprehensive RI/FS is required. Generally, this
determination will depend on whether the site is suitable
for a streamlined risk evaluation, as described on page
4. The community, state, and potentially responsible
parties (PRPs) should be notified  that a presumptive
remedy is being considered for the  site before work on
the RI/FS work plan is initiated. The notification may
take the form of a fact sheet, a notoice in a local newspaper,
and/or a public meeting.

Use of the presumptive remedy eliminates the need for
the initial  identification and screening of alternatives
during the feasibility study (FS).  Section 300.430(e)(l)
of the NCP states that,  "...  the lead agency shall include
art alternatives  screening step, when needed, (emphasis
added) to select a reasonable number of alternatives for
detailed analysis."

EPA conducted an analysis of potentially available
technologies for municipal landfills and found that
certain technologies are routinely and appropriately
screened out on the basis of effectiveness, feasibility, or
cost (NCP Section 300.430(e)(7)). (See Appendix A to
this directive and "Feasibility Study Analysis for
CERCLA Municipal Landfills," September 1993
available at EPA Headquarters and Regional Offices.)
Based on this analysis, the universe of alternatives that
will be analyzed in  detail may be limited to the
components  of the containment remedy  identified in
Highlight 1, unless  site-specific  conditions dictate
otherwise or alternatives are considered that were not
addressed in the FS analysis. The FS analysis document,
together with  this directive, must be included in the
administrative record for each municipal landfill
presumptive remedy site to support elimination of the
initial identification and screening  of site-specific
alternatives. Further detailed  and comprehensive

supporting materials (e.g., FS reports included in
analysis, technical reports) can be provided by
Headquarters, as needed.

While the universe of alternatives to address the landfill
source will be limited to those components identified in
Highlight 1, potential alternatives that may exist for each
component or combinations of components may be
evaluated in the detailed analysis. For example, one
component of the presumptive remedy is source area
ground-water control.  If appropriate, this component
may be accomplished in a number of ways, including
pump  and treat, slurry walls, etc.  These potential
alternatives  may then be combined with other components
of the presumptive remedy  to develop a range of
containment alternatives suitable for site-specific
conditions.  Response alternatives must then be evaluated
in detail against the nine criteria identified in Section
300.430(e)(g) of the NCP. The detailed analysis will
identify site-specific ARARs and develop costs on the
basis of the particular size and volume of the landfill.


EPA has identifies the presumptive remedy site categories
as good candidates for early action under SACM. At
municipal landfills, the upfront knowledge that the source
area will be contained may facilitate  such early actions as
installation of a landfill cap or a ground-water containment
system. Depending on  the circumstances, early actions
may be accomplished using either removal  authority
(e.g., non-time-critical removal actions) or remedial
authority. In some cases, it may be appropriate for an
Engineering Evaluation/Cost Analysis to replace part or
all of the RI/FS if the source control  component will be a
non-time-critical removal action. Some  factors may affect
whether a specific response action would be better
accomplished as a removal or remedial action including
the  size of the action, the associated  state cost share, and/
or the scope of O&M.  A discussion of these factors is
contained in Early Action and Long-term Action Under
SACM-Interim Guidance,  Publication No. 9203.1-051,
December 1992.


The goal of an RI/FS is to provide the information
necessary to: (1) adequately characterize the  site; (2)
define site dynamics; (3) define risks; and (4) develop the
response action. As discussed in the following sections,
the process for achieving each of these goals can be
streamlined for CERCLA municipal landfill sites  because
of the upfront presumption that landfill contents will be
contained.  The strategy for streamlining each of these
areas should be developed early (i.e., during the scoping
phase of the RI/FS).

1. Characterizing the Site

The use of existing data is especially important in
conducting a streamlined RI/FS for municipal landfills.
Characterization of a landfill's contents is not necessary
or appropriate for selecting a response action for these
sites except in limited cases; rather, existing data are used
to determine whether the containment presumption is
appropriate. Subsequent sampling  efforts should focus
on characterizing areas where  contaminant migration is
suspected, such  as leachate discharge  areas or areas
where surface water runoff has caused erosion. It is
important to note that the decision to characterize hot
spots should also be based on existing information, such
as reliable anecdotal information, documentation, and/or
physical evidence (see page 6).

In those limited cases where no information is available
for a site, it may not be advisable to initiate use of the
presumptive remedy until some data are collected.  For
example, if there is extensive migration of contaminants
from a site located in an area with several sources, it will
be necessary to have some information about the landfill
source in order to make an association between on-site
and off-site contamination.

Sources of information of particular interest during
scoping include  records of previous ownership, state
files, closure plans, etc., which may  help to  determine
types and sources of hazardous materials present. In
addition, a site visit is appropriate for several  reasons,
including the verification of existing data, the identification
of existing site remediation systems, and to visually
characterize wastes  (e.g.,  leachate seeps).  Specific
information to be collected is  provided in Sections  2.1
through 2.4 of the municipal landfill manual.

2. Defining Site Dynamics

The collected data are used to develop a conceptual  site
model, which is the key component of a streamlined
RI/FS. The conceptual site model is an effective tool for
defining the site dynamics, streamlining the risk
evaluation, and developing the response action. Highlight
2 presents a generic conceptual site model for municipal
landfill. The model is developed before any RI field
activities are conducted,  and its purpose is to aid in
understanding  and describing the site and to present
hypotheses regarding:

    •   The suspected sources and types of
        contaminants present;

        Contaminant release  and transport

                         Highlight  2: Generic Conceptual Site Model
        Rate of contaminant release and transport
        (where possible);

    •   Affected media;

    •   Known and potential routes of migration;

    •   Known and potential human and
        environmental receptors.

After the data are evaluated and a site visit is completed,
the contaminant release and transport mechanisms relevant
to the site should be determined. The key element in
developing the conceptual site model is to identify those
aspects  of the model that require more information to
make a decision about response measures. Because
containment of the landfill's contents is the presumed
response action, the conceptual site model will be of most
use in identifying areas beyond the landfill  source itself
that will require further study, thereby focusing site
characterization away from the source area and on areas
of potential contaminant migration (e.g., ground water or
contaminated sediments).
                                           3. Defining Risks

                                           The municipal landfill manual states that a streamlined or
                                           limited baseline risk assessment will be sufficient  to
                                           initiate response action on the most obvious problems at
                                           a municipal landfill (e.g., ground water, leachate, landfill
                                           contents,  and landfill gas). One method for establishing
                                           risk using a streamlined approach is to compare
                                           contaminant concentration levels (if available) to standards
                                           that are potential chemical-specific applicable or relevant
                                           and appropriate requirements (ARARs) for the action.
                                           The manual states that where established standards for
                                           one or more contaminants in a given medium are clearly
                                           exceeded, remedial action generally is warranted.3

                                           It is important to note, however, that based on  site-
                                           specific conditions, an active response is not required if
                                           ground-water contaminant concentrations exceed
                                           chemical-specific standards but the site risk is within the
                                           Agency's acceptable risk range (10"4to 10"'). For
                                           example, if it  is determined that the release of
                                                            'See also OSWER Directive 9355.0-30, Role of the Baseline Risk
                                                            Assessment in Superfund Remedy Selection Decisions, April 22,
                                                            1991, which states that if MCLs or non-zero MCLGs are exceeded, [a
                                                            response] action  generally is warranted.

contaminants from a particular landfill is declining, and
concentrations of one or more ground-water contaminants
are at or barely exceed chemical-specific  standards, the
Agency may decide  not to implement an active response.
Such a decision might be based on the understanding that
the landfill is no longer acting as a source of ground-water
contamination, and that the landfill does not present an
unacceptable risk from any  other exposure pathway.

A site generally will not be eligible for a streamlined risk
evaluation if ground-water contaminant concentrations
do not clearly exceed chemical-specific standards or the
Agency's accepted level of risk,  or other  conditions do
not exist that provide a clear justification for  action (e.g.,
direct contact with landfill contents resulting from unstable
slopes). Under  these circumstances, a quantitative risk
assessment that addresses all exposure pathways will be
necessary to determine whether action is needed.

Ultimately, it is necessary to demonstrate that the  final
remedy addresses all pathways and contaminants of
concern, not just those that triggered the remedial action.
As described in the following sections, the conceptual
site model  is an effective tool for identifying those
pathways and illustrating that they have been addressed
by the containment  remedy.

Streamlined Risk Evaluation Of The  Landfill
Experience from the presumptive remedy pilots supports
the usefulness of a streamlined risk evaluation to initiate
an early response action under certain circumstances. As
a matter 01  policy, for the source area of municipal
landfills, a quantitative risk assessment that considers all
chemicals, their potential additive effects,  etc., is not
necessary to establish a basis for action if ground-water
data are available to  demonstrate that contaminants clearly
exceed  established standards or if other conditions  exist
that provide a clear justification for action.

A quantitative risk  assessment also is not necessary to
evaluate whether the containment remedy addresses all
pathways and contaminants of concern associated  with
the source. Rather, all potential exposure  pathways can be
identified using the conceptual site model and compared
to the pathways addressed by the containment  presumptive
remedy. Highlight 3  illustrates that the containment remedy
addresses all exposure pathways associated with the
source at municipal landfill sites.

Finally, a quantitative risk assessment is not required to
determine clean-up levels because the type of cap will be
determined by closure ARARs, and ground water that is
extracted as  a component of the presumptive  remedy will
be required to meet discharge limits, or other standards for
its  disposal. Calculation of clean-up levels  for ground-
water contamination that has migrated away from the
source will not be accomplished  under the presumptive
     Highlight 3: Source Contaminant
     Exposure Pathways Addressed
     by Presumptive Remedy
      1.    Direct contact with soil and/or
            debris prevented by landfill cap;
      2.    Exposure to contaminated ground
            water within the landfill area
            prevented  by  ground-water
      3.    Exposure  to   contaminated
            leachate prevented by leachate
            collection  and treatment; and
      4.    Exposure  to   landfill  gas
            addressed  by gas  collection  and
            treatment,  as  appropriate.
remedy, since such contamination will require  a
conventional investigation and a risk assessment.

Streamlining the risk assessment of the source area
eliminates the need for sampling and analysis to support
the calculation of current or potential future risk associated
with direct contact. It is important to note that because the
continued effectiveness of the containment remedy
depends on the integrity of the containment system, it is
likely that institutional controls will be  necessary to
restrict future activities at a CERCLA municipal landfill
after construction of the cap and associated  systems. EPA
has thus determined that it is not appropriate or necessary
to estimate the risk associated with future residential use
of the landfill source, as such use would be incompatible
with the need to maintain the  integrity of the containment
system. (Long-term waste management areas, such as
municipal landfills, may be appropriate,  however, for
recreational or other limited uses on  a site-specific basis.)
The availability  and efficacy of institutional controls
should be evaluated  in the  FS. Decision documents
should include measures such as institutional controls to
ensure the continued integrity of such containment systems
whenever possible.

Areas of Contaminant Migration
Almost every municipal landfill site has some characteristic
that may require additional study, such as leachate
discharge to a wetland  or significant  surface water run-off
caused by  drainage problems. These migration pathways,
as well as ground-water contamination that has migrated
away  from the  source,  generally will  require
characterization and a more comprehensive risk assessment
to determine whether action is warranted beyond the
source area and, if so, the type of action that is appropriate.

While future residential use  of the landfill source area
itself is not considered appropriate, the land adjacent to

landfills is frequently used for residential purposes.
Therefore, based on site-specific circumstances, it may be
appropriate to consider future residential use for ground
water and other exposure pathways when assessing risk
from areas of contaminant migration.

4. Developing the Response Action

As a first step in developing containment alternatives,
response action objectives should be developed on the
basis of the pathways identified for action in the
conceptual  site model. Typically, the primary response
action objectives for municipal landfill sites include:

              Presumptive  Remedy

      •     Preventing direct contact with landfill

      •     Minimizing infiltration and resulting
           contaminant leaching to ground water;

      •     Controlling surface water runoff and

      •     Collecting and treating contaminated
           ground water and  leachate  to contain
           the contaminant plume and prevent
           further migration from source area;

      •     Controlling and treating landfill gas.
             Non-Presumptive Remedy

     •    Remediating ground water;

     •    Remediating contaminated surface
          water and sediments; and

     •    Remediating contaminated wetland

As discussed in Section 3, "Defining Risks," the
containment  presumptive remedy accomplishes all but
the last three of these  objectives by addressing all
pathways associated with the source. Therefore, the
focus of the RI/FS can be shifted to characterizing the
media  addressed in  the  last  three  objectives
(contaminated  ground water, surface  water  and
sediments, and wetland areas) and on collecting data to
support design of the containment remedy.

Treatment of Hot Spots

The decision to characterize and/or treat hot spots is a
site-specific judgement that should be based on the
consideration of a standard set of factors. Highlight 4
lists questions that should be answered before making
the decision to characterize and/or treat hot spots. The
overriding question is whether the combination of the
waste's physical and chemical characteristics and volume
is such that the integrity of the new containment system
will be threatened if the waste is left in place. This
question should be answered on the basis of what is
known about a site (e.g., from operating records or other
reliable information). An answer in the affirmative to all
of the questions listed in Highlight 4 would indicate that
it is likely that the integrity of the containment system
would be threatened, or that excavation and treatment of
hot spots would be practicable, and that a significant
reduction in risk at the site would occur as a result of
treating hot spots. EPA  expects that few CERCLA
municipal landfills will fall into this category; rather,
based on the Agency's experience, the majority of sites
are expected to be suitable for containment only, based
on the heterogeneity of the waste, the lack of reliable
information concerning disposal history, and the
problems associated with excavating through refuse.

The volume of industrial and/or hazardous waste co-
disposed with municipal waste at CERCLA municipal
landfills varies from site to site, as does the amount of
information available concerning disposal history.  It is
impossible to fully characterize, excavate, and/or treat
the source area of municipal landfills, so uncertainty
about the landfill contents is expected. Uncertainty by
itself does not call into question the containment
approach. However, containment remedies must be
designed to  take into account the possibility  that hot
spots are present in addition to those that have been
identified and characterized. The presumptive remedy
must be relied upon to contain landfill contents and
prevent migration of comtaminants. This is accomplished
by a combination of measures, such as a landfill cap
combined with a leachate  collection system. Monitoring
will further ensure the continued effectiveness of the

The following examples illustrate site-specific  decision
making and show how these factors affect the  decision
whether to characterize and/or treat hot spots.

Examples of Site-Specific Decision Making
Concerning Hot Spot Characterization/

Site A

There is anecdotal information that approximately 200
drums of hazardous waste were disposed of at this 70-
acre former municipal landfill, but their location and
contents are unknown. The remedy includes a landfill cap
and ground-water and landfill gas treatment.

A search for and characterization of hot spots is not
supported at Site A based on the questions listed in

      Highlight 4:  Characterization
      of Hot Spots
      If all of the following questions can be
      answered in the affirmative, it is likely
      that characterization and/or treatment
      of hot spots is warranted:

      1.    Does evidence  exist to  indicate
          the presence and approximate
           location of waste?

      2.    Is the hot spot  known to  be
           principal threat waste?*

      3.    Is the  waste  in a  discrete,
           accessible part  of the landfill?

      4.    Is the hot spot known to  be  large
           enough that its  remediation will
           reduce  the threat posed by the
           overall site but small enough that
           it is reasonable to consider
           removal  (e.g.,  100,000 cubic
           yards or less)?

 *See A Guide to Principal Threat and Low
 Level Threat Wastes, November  1991,
 Superfund Publication No. 9380.3-06FS.
Highlight 4: (1) no reliable information exists to indicate
the location of the waste; (2) the determination of whether
the waste is principal threat waste cannot be made since
the physical/chemical  characteristics of the  wastes are
unknown; (3) since the  location of the waste is unknown,
the determination of whether the waste is in a discrete
accessible  location cannot be made; (4) in this ease, the
presence of 200 drums in a 70-acre landfill is not considered
to significantly affect the threat posed by the overall site.
Rather, the containment system will include measures to
ensure its continued effectiveness (e.g.,  monitoring and/or
leachate collection) given the  uncertainty associated with
the landfill contents  and suspected drums.


Approximately  35,000 drums,  many containing hazardous
wastes, were disposed of in two drum disposal units at this
privately owned 80-acre inactive landfill, which was
licensed to receive general refuse. The site is divided into
two operable units. The remedy for Operable Unit 1 (OU
1) is incineration of drummed wastes in the two drum
disposal units. The remedy for OU 2 consists of treatment
of contaminated ground  water  and leachate and
containment of treatment residuals (from OU 1) and
remaining landfill contents, including passive  gas
collection and flaring.

Treatment of landfill  contents is supported at Site B
because all of the questions in Highlight 4 can be answered
in the affirmative:  (1) existing evidence from  previous
investigations and sampling conducted by the  state (prior
to the RI) indicated  the presence and approximate location
of wastes; (2) the wastes were  considered principal threat
wastes because  they were liquids and (based on sampling)
were believed to contain contaminants of concern; (3) the
waste is located in discrete accessible parts of the landfill;
and (4) the waste volume is large enough that its
remediation will significantly reduce the threat posed
by the overall  site.


Subtitle D

In the absence  of Federal Subtitle D closure regulations,
State Subtitle  D closure requirements generally have
governed CERCLA  response actions at municipal landfills
as applicable or relevant and  appropriate requirements
(ARARs). New Federal Subtitle D closure and post-
closure care regulations will be in effect on October 9,
1993 (56 FR 50978 and 40 CFR 258)." State closure
requirements that are ARARs and that are more  stringent
than the Federal requirements must be attained or waived.

The new Federal regulations  contain requirements related
to construction and maintenance of the final  cover, and
leachate collection, ground-water monitoring, and gas
monitoring systems. The final cover regulations willbe
applicable requirements for landfills that received
household waste after October 9,1991. EPA expects that
the final  cover requirements will be applicable to few, if
any, CERCLA municipal landfills, since the receipt of
household wastes  ceased at most  CERCLA  landfills
before October  1991. Rather, the substantive requirements
of the new  Subtitle D regulations generally will be
considered relevant and approptiate requirements for
CERCLA response actions that occur after the effective date.

Subtitle  C

RCRA Subtitle C closure requirements may be applicable
or relevant  and appropriate in certain circumstances.
RCRA Subtitle C is applicable if the landfill received
waste that is  a listed or characteristic waste under
RCRA, and:

1. The waste was disposed  of after November 19,1980
    (effective date of RCRA), or
4An extension of the effective date has been proposed but not
finalized at this time.

2. The new response action constitutes disposal under
   RCRA (i.e., disposal back into the original landfill).3

The decision about whether a Subtitle C closure
requirement is relevant  and appropriate is based on a
variety of factors, including the nature of the waste and its
hazardous properties, the date on which it was disposed,
and the nature of the requirement itself. For more
information on RCRA Subtitle C closure requirements,
see RCRA ARARs:Focus on Closure Requirements,
Directive No.  9234.2-04FS, October 1989.
'Note that disposal of only small quantity hazardous waste and
household hazardous waste does not make Subtitle C applicable.

   The policies set out in this document are intended solely as guidance to the U.S. Environmental
   Protection Agency (EPA) personnel; they are not final  EPA actions and do not constitute rulemaking.
   These policies are not intended, nor can they be relied upon, to  create any rights enforceable by any party
   in litigation with the  United  States. EPA officials may  decide to follow the guidance  provided in this
   document, or to act at variance with the guidance, based on an analysis of specific site circumstances.
   EPA also reserves the right to change the guidance at any time without public notice.

                                      APPENDIX A
     This Appendix summarizes the analysis that EPA conducted of feasibility study (FS) and Record
of Decision (ROD) data from CERCLA municipal landfill sites which led to the establishment of
containment as the presumptive remedy for these sites. The objective of the study was to identify those
technologies that are consistently included in the remedies selected, those that are consistently
screened out, and to identify the basis for their elimination.  Results of this analysis support the decision
to eliminate the  initial technology identification and screening  steps on a site-specific basis for this site
type. The technical review found that certain technologies are appropriately screened out based on
effectiveness, implementability,  or excessive costs.

     The methodology for this analysis entailed reviewing  the  technology identification  and screening
components of the remedy selection process for a representative sample of municipal landfill sites. The
number of times each technology was either screened out or selected in each remedy was compiled.
A detailed discussion of the methodology used is provided below.


Identification of Sites for Feasibility Study Analysis

        Of the 230 municipal landfill sites on the NPL, 149 sites have had a remedy selected for at least
one operable unit. Of the 149 sites, 30 were selected for this study on a random basis, or slightly greater
than 20 percent. The sites range in size from 8.5 acres to  over 200 acres and are located primarily in
Regions 1,2,3, and 5. This geographical distribution approximates the distribution of municipal  landfills
on the NPL.

Technology Secrrning  and Remedial Alternative Analysis

        The FS analysis involved a review of the technology identification and screening phase,
including any pre-screening steps, followed by a review of the detailed  analysis and comparative
analysis phases. Information derived from each  review was documented on site-specific data collection
forms, which are available for evaluation as part of the Administrative Record for this presumptive
remedy directive.  The review focused on the landfill source contamination only;  ground-water
technologies and alternatives were not included in the analysis.

        For the screening phase, the full range of technologies considered was listed on the data
collection forms, along with the key reasons given for eliminating technologies from further consider-
ation. These reasons were categorized according to the screening criteria: cost, effectiveness, or
implementability. The frequency with which specific reasons were  given for eliminating a technology
from further consideration was then tallied and compiled into a screening phase summary table.

        For the detailed analysis and comparative analysis, information on the relative performance of
each technology/alternative with respect to the seven NCP  criteria was documented on the site-specific
data collection forms. The advantages and disadvantages  associated with each clean-up option  were
highlighted. In some cases, a technology was combined with one or more technologies into one or more
alternatives. The disadvantages of a technology/alternative were then compiled into a detailed
analysis/comparative  analysis summary table, under the assumption that these disadvantages
contributed to non-selection. All summary tables are available for review as part of the  Administrative

                                      APPENDIX A


       The information from the technology screening and remedial alternative analyses  is provided
in Table 1. It demonstrates that containment (the presumptive remedy), was chosen as a  component
of the selected  remedy at all thirty of the sites analyzed.  No other technologies or treatments were
consistently selected as a remedy or retained for consideration in a remedial alternative. However,  at
eight of the thirty sites, there were circumstances where technologies were included in the selected
remedy to address a site-specific concern, such as principal threat wastes. These technologies are
included in the column entitled "Tech. Not Primary Component of Alternative"1 in Table  1 and include
incineration at two sites, waste removal and off-site disposal at two sites, soil vapor extraction at two
sites, and  bioreclamation at  one site.

       Leachate collection and gas collection systems were also tracked as part of the detailed
analysis and comparison of remedial alternatives.   These types of systems generally were not
considered as  remediation technologies during the screening phases. At fifteen sites, leachate
collection was selected as part of the overall containment  remedy. At seventeen sites, gas collection
systems were selected as part of the overall containment  remedy.

       This  analysis supports the decision to eliminate the initial technology identification and
screening step for municipal landfill sites.  On  a site-specific basis, consideration of remediation
technologies  may be retained as needed.

1 This column title is used for record-keeping purposes only and is not meant to imply that these treatment
 technologies  are not considered important components of the selected remedies.

                                                         /    #RODs WHERE CRITERION CONTRIBUTED TO NON-SELECTION

                                                                       #RODs WHERE CRITERION CONTRIBUTED™ NON-SELECTION

Offsite RCRA
Offsite Landfill
Onsite RCRA
 Onsite Landfill

                                                                        #RODs WHERE CRITERION CONTRIBUTED TO NON-SELECTION
 Low Temperature
 Thermal Desorp/
 In-situ Steam

                                                                     /#RODs WHERE CRITERION CONTRIBUTED TO NON-SELECTION
Soil Vapor