CERCLA Section 121(d)(2) specifies that on-site Superfund remedial actions shall attain "other Federal standards,
requirements, criteria, limitations, or more stringent State requirements that are determined to be legally applicable
or relevant and appropriate (ARAR) to the specified circumstances at the site." In addition, the National Contingency
Plan (NCP) requires that on-site removal actions attain ARARs to the extent practicable. Off-site removal and
remedial actions must comply with legally applicable requirements. This guide outlines the process used to determine
whether the Resource Conservation and Recovery Act (RCRA) land disposal restrictions (LDRs) established under
the Hazardous and Solid Waste Amendments (HSWA) are "relevant and appropriate" to an on-site CERCLA response
action. (See Superfund LDR Guide #5 for determining when LDRs are applicable to CERCLA response actions.)
The guide also provides examples of when the LDRs are likely to be relevant and appropriate and when they are not.
With respect to contaminated soil and debris, EPA is undertaking a rulemaking to establish specific LDRs; until this
rulemaking is completed, EPA generally will not consider the LDRs to be relevant and appropriate for soil and debris
contaminated with hazardous substances that are not RCRA restricted wastes. More detailed guidance on Superfund
compliance with the LDRs is being prepared by the Office of Solid Waste and Emergency Response (OSWER).
United States	Office of	Superfund Publication:
Environmental Protection	Solid Waste and	9347.3-08FS
Agency	Emergency Response	December 1989
vEPA	Superfund LDR Guide #7
Determining When Land Disposal
Restrictions (LDRs) Are Relevant
and Appropriate to CERCLA
Response Actions
LDR RELEVANT AND APPROPRIATE
DETERMINATIONS
For on-site CERCLA responses that constitute
placement, and for which the LDRs have been
determined not to be applicable (i.e., the wastes being
placed are not prohibited or restricted RCRA wastes),
site managers should evaluate whether the LDRs are
relevant and appropriate. As discussed in the
CERCLA Compliance with Other Laws Manual (EPA,
August 8, 1988), relevant and appropriate decisions
require best professional judgment of site-specific
factors to determine whether a requirement addresses
problems or situations sufficiently similar to the
circumstances of the release, or remedial action
contemplated, and is well-suited to the site, and
therefore, is both relevant and appropriate.
Section 300.400(g)(2) of the proposed NCP [53 FR
at 51436 (December 21, 1988)] outlines a number of
factors pertaining to CERCLA situations and potential
ARARs which should be compared to determine
whether a requirement is both relevant and
appropriate. The four pertinent factors to compare
when evaluating the potential relevance and
appropriateness of the LDRs are: (1) the action or
activities regulated by the requirement (e.g., placement
on the land) and the remedial action contemplated; (2)
the purpose of the requirement and the purpose of the
CERCLA action; (3) the substances regulated by the
requirement and the substances found at the CERCLA
site; and (4) the medium regulated or affected by the
requirement and the medium contaminated or affected
at the CERCLA site. These factors are evaluated to
determine whether the circumstances of the release
and remedial action contemplated are such that use of
the LDR requirements is well-suited to CERCLA
response objectives.
The evaluation of the circumstances of a release
is conducted as part of the remedial investigation,
during which information is collected on contaminant
sources, potential routes of migration, and potential
human and environmental receptors of concern. The
results of this effort (which is ultimately documented
in the site characterization and baseline risk assessment
chapters of the RI/FS report) are used to establish
remedial action objectives for the areas or media
contaminated at the site that pose a threat to human
health and the environment. The site-specific
CERCLA response objectives of the remedial action
contemplated should be compared with the purpose or
objectives of the LDRs as a first step in determining
the potential relevance and appropriateness of the
LDRs [proposed NCP factors (a) and (e)].
The objective of the LDRs is to achieve
reductions in the toxicity and/or mobility of a
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hazardous waste, based on application of the best
demonstrated available technology (BDAT), prior to its
land disposal. While this objective will often be
compatible with remedial alternatives designed to
destroy highly concentrated, toxic, and mobile materials
such as liquids, other remedial alternatives involving
treatment of the principal threats of a site may have
different objectives to which the LDRs are not well-
suited.
Once a decision is made that achieving BDAT
reductions in the toxicity and/or mobility of a waste
source is compatible with CERCLA response objectives
for the site, site managers should utilize information on
waste constituents and matrices collected as part of the
site characterization to evaluate whether a CERCLA
waste is “sufficiently similar” to a listed RCRA waste
code or family of waste codes (e.g., K048-K052,
petroleum refining wastes) such that the LDR standard
for that waste code is appropriate for the CERCLA
waste.
In determining whether a CERCLA waste is
sufficiently similar, site managers should consider
whether the BDAT used to set the LDR standard
would be effective for the CERCLA waste.
(Technologies other than those used to set the BDAT
;tandards may be considered, although they must be
regarded as capable of meeting the promulgated
oncentration requirements.) Although a constituent-
ty-constituent analysis is not necessary for relevant
md appropriate determinations, a general comparison
)f the waste constituents and matrices is useful for
dentifying waste codes to which a CERCLA waste may
)e similar, and therefore, helpful in the identification
)f technologies that may be appropriate for
;onsideration.
If a CERCLA waste that consists of a complex
nixture of several different wastes occurs in a different
nedium (e.g., soil) or matrix (BDAT standards may be
:stablished for specified matrices, such as wastewaters,
onwastewaters, or both) from what is specified for a
)articular restricted waste code or contains
acompatible waste constituents, use of BDAT may not
‘e appropriate for that waste, and therefore, the LDRs
NOTE: If the LDRs are determined to be
relevant and appropriate requirements for a
CERCLA action (i.e., there is a close match
between the CERCLA and LDR objectives, and
a close match between the constituents/matrix of
the CERCLA waste and the constituents/matrix
of the relevant RCRA waste code), but the
treatment process involved in the remedy does
not achieve BDAT levels in the field as
anticipated, a Treatability Variance establishing
alternate treatment levels should be sought.
would not be relevant and appropriate [ proposed NCP
factor (b)]. It has been the experience of the
Superfund program that Treatability Variances are
frequently necessary for soil and debris contaminated
with a restricted RCRA waste (see Superfund LDR
Guide #6A), because the promulgated LDR standards
are based on treating less complex matrices of
industrial process wastes. As a logical corollary to this
fmding, the Agency believes that LDRs generally would
not be “relevant and appropriate” requirements for soil
and debris contaminated with p -RCRA restricted
wastes. However, the Agency plans to undertake a
rulemaking that will prescribe applicable standards for
the treatment of soil and debris contaminated with
RCRA-restricted wastes. In the future, these standards
may be relevant and appropriate to the treatment of
soil and debris contaminated with non-restricted wastes.
Examples illustrating the relevant and appropriate
determination process follow:
• A number of drums containing hazardous wastes
are discovered during a site investigation.
Although no written documentation or specific
knowledge of the soutce is available to identify
with certainty the origins of the wastes, the
laboratory analyses indicate that they contain very
high concentrations of a pr dominantly liquid
waste indicative of industrial, waste streams.
Therefore, maximum destruction of the drum
contents is established as the remedial action
objective. Due to the general similarity of the
bulk liquids to the spent solvents listed in the
FOO1-F005 waste codes, the CERCLA site
manager determines that use of incineration (one
of the BDAT identified in the solvent and dioxin
rule for that family of waste codes) would be
technically suitable. Therefore, the LDRs would
be relevant and appropriate for an alternative
involving the treatment and placement of the
drummed waste.
• A CERCLA waste mixture from an unknown
source is found to consist of wastes similar to
F021 dioxin-containing wastes (i.e., they contain
constituents found in dioxin-containing wastes)
and mercury. Because use of incineration -- the
BDAT for dioxin-containing wastes - - would not
be compatible with a waste also containing
mercury, application of the LDR treatment
standards to this waste mixture would not be
appropriate. Therefore, the LDRs would not be
relevant and appropriate to a CERCLA response
involving the placement of this waste mixture.
(Alternate methods of treating the waste might
still be necessary to satisfy both the CERCLA
statutory requirement to utilize treatment to the
maximum extent practicable and the program
expectations that are outlined in the proposed
NCP.)

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