UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
SOLID WASTE AND EMERGENCY RESPONSE
SEP -11993
OSWER Directive No. 9835.15b
MEMORANDUM
SUBJECT t
FROM:
o
New Policy on Performance of
Remedial Investigatioii/Feasil
Conducted by Potentially Resi
Richard J. Guimond
Assistant Surgeon General, USPfts
Acting Assistant Administrator
lisk Assessments During
Llity Studies (RI/FS)
isible Parties (PRPs)
TO:	Regional Administrators, Regions I-x
Purpose
This memorandum announces EPA's new policy on conducting
risk assessments at Superfund sites where PRPs are conducting the
RI/FS and the Agency's reasons for adopting this policy. This
supplements and supersedes in part the policy stated in
"Performance of Risk Assessments in RI/FSs Conducted by PRPs,"
OSWER Directive No. 9835.15 (August 28, 1990).
Background
On June 21, 1990, EPA announced that thereafter it (or a
state if designated) would conduct the risk assessment portion of
the RI/FS in all cases, and would not allow risk assessments to
be performed by PRPs. That policy was later elaborated upon in
OSWER Directive No. 9835.15. The policy was challenged in
litigation brought by the Chemical Manufacturers' Association and
others. In December 1991, EPA entered into a settlement of that
litigation under which it agreed to evaluate and reassess the
1990 risk assessment policy.
The EPA/CMA settlement committed EPA to evaluate the 1990
policy and to provide an opportunity for public comment on the
pre-1990 and post-1990 policies as well as on the results of
EPA's evaluation. EPA's evaluation included a review of timing,
coordination, and settlement issues relating to both EPA and PRP-
conducted risk assessments within PRP-lead RI/FS projects. EPA
evaluated RI/FSs commenced both before and after June 21, 1990.
The specific findings and conclusions of EPA's evaluation are

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contained in the "1992 Risk Assessment Evaluation Report," dated
March 9, 1993.
EPA recognizes the critical role that the risk assessment
plays in site cleanups. Prior to the 1990 policy, EPA relied
upon oversight to ensure that PRP-conducted risk assessments
measured site risks appropriately. EPA adopted the 1990 policy
to reduce delays and resource demands involved in finalizing risk
assessments performed by PRPs. Although the 1990 policy did
reduce the number of PRP documents to be reviewed and the delays
associated with EPA review and approval, data obtained through
the risk assessment evaluation report indicate that other delays
are created when EPA conducts the risk assessment. Specifically,
the available data shows that additional delays were generated
during data transfer between EPA and PRPs.
New Policy for Orders or Decrees for PRP RI/FS
l) General statement of Policy
It remains EPA's position that, for reasons stated below, it
is generally more appropriate for risk assessments to be
conducted by EPA than by PRPs, even where PRPs are performing the
remainder of the RI/FS. However, effective immediately, EPA may,
in appropriate cases, enter into orders for PRP RI/FSs under
which risk assessments can be conducted by PRPs. To the extent
that OSWER Directive No. 9835.15 precludes doing so, it is hereby
superseded. Suggested criteria are discussed below for
determining whether allowing a PRP to conduct a risk assessment
is appropriate in a given case.
If, under the terms of an order, PRPs are given an
opportunity to conduct the risk assessment, EPA will perform
stringent oversight and require appropriate PRP deliverables as
outlined in "Guidance on Oversight of PRP RI/FSs," OSWER
Directive No. 9835.1(c), July 1991. EPA will review and provide
comments to PRPs on their deliverables in a timely fashion, in
order to minimize the potential for delays.
If the Region chooses to conduct the risk assessment itself
at a particular site, it should adhere to the remaining
applicable portions of the August 28, 1990 and July 2, 1991
directives (OSWER Nos. 9835.15 and 9835.15a, respectively). This
includes providing PRPs with EPA risk assessment interim
deliverables. This will serve to facilitate early resolution of
risk assessment issues and minimize the potential for delays
during the RI/FS.
This policy also applies to the risk evaluation or risk
assessment portion of an Engineering Evaluation and Cost Analysis
(EE/CA) performed by PRPs. This policy does not, nor did the
previous policies, apply to risk assessments at Federal facility

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sites. The term "risk assessment" in this directive includes
ecological risk assessments as well as assessments of risks to
human health.
2) Site-specific Considerations
EPA's determination on whether to allow a PRP to conduct the
risk assessment will be made on a site-by-site basis, using site-
specific considerations. These considerations will ensure
compliance with section 104(a)(1) of CERCLA which states that "no
remedial investigation or feasibility study (RI/FS) shall be
authorized except on a determination by the President that the
party is qualified to conduct the RI/FS." Criteria to be
considered should generally include:
o EPA's prior experience with the requesting PRPs at this or
other sites and in particular whether excessive oversight
and revisions were necessary when that PRP previously
conducted a risk assessment;
o PRP or PRP contractor's experience in conducting Superfund
risk assessments;
o PRP or PRP contractor's knowledge of current Superfund
risk assessment processes and guidance documents;
o PRP or PRP contractor's ability to submit data to EPA in the
proper format; and
o Available EPA resources and schedule for RI/FS completion.
In addition, Regions may consider other factors such as the level
of public concern at the site. To facilitate this determination,
Regions may request that PRPs submit information on all of the
relevant criteria.
The site-specific decision on whether to allow PRPs to
conduct the risk assessment is a matter of Agency discretion.
This Agency policy does not confer any legal rights upon private
parties to perform risk assessments. Regional staff should
briefly document their response to a PRP's request to perform the
risk assessment based on the above criteria and any other
criteria the Region considers appropriate.
3) Headquarters Consultation Requirements
Before agreeing to an EPA-PRP order allowing PRPs to perform
the risk assessment, an EPA Region must consult with the OWPE
Office Director. The Region must provide a memorandum
documenting the basis for its decision.

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4) RI/F8 Order Documentation Requirements
For new consent orders where PRPs are allowed to conduct the
risk assessment, EPA will follow the existing procedures (e.g.,
certification of the PRP risk assessment) contained in the August
28, 1990 directive. EPA's new policy reemphasizes the use of
EPA's penalty and takeover procedures in case of PRP non-
compliance with the terms of the order.
Consent orders already in existence for PRP RI/FSs may be
amended to allow PRPs to conduct the risk assessment. In these
situations, however, Regions must consider the available EPA
oversight resources and schedule to complete the RI/FS before
amending an order.
Basis for New Policy
In developing this policy, OSWER considered several sources
of information, including among other things: 1) public comments
on the merits of the pre- and post-June 21, 1990 policies, 2) the
results of its risk assessment evaluation, 3) the results of its
Regional survey, and 4) public comments on the risk assessment
evaluation report. Each of these contained information weighing
both for and against allowing PRPs to conduct risk assessments.
EPA's principal concern cited in the 1990 policy was that
when PRPs conducted the risk assessment, extensive EPA oversight
and repeated revisions of the risk assessment were required to
obtain a satisfactory product. EPA's March 1993 evaluation of
the 1990 policy attempted to measure the delay associated with
PRP risk assessments, as well as considering delays and
coordination problems arising from EPA risk assessments. In
general, the evaluation found that the need for oversight and
revisions significantly affected the time required for completion
of PRP risk assessments. At the same time, it was found that
coordination problems with PRPs (in particular, data transfer)
caused delays at sites where EPA conducted risk assessments.
EPA believes that procedures can be developed to reduce
delays resulting from data transfer; some Regions have already
developed such procedures. Over time, therefore, EPA expects the
timing advantages of EPA-conducted risk assessments will become
more apparent.
Furthermore, an underlying concern remains about the level
of public confidence in risk assessments performed by PRPs.
Because the risk assessment is a central component of the
response decision, EPA places great importance upon a high level
of public confidence in the risk assessment. Because risk
assessments are complex technical documents involving difficult
and subtle professional judgments, it can be difficult for the
public to evaluate the accuracy cf a risk assessment. When the

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party performing the risk assessment has a financial incentive to
minimize the cost of the response, it is foreseeable that, in
many cases, the public may be skeptical about its reliability,
and the difficulty of evaluating the risk assessment makes such
skepticism difficult to dispel.
EPA can attempt to address public concerns by overseeing the
preparation of the risk assessment. The Risk Assessment Guidance
for Superfund (RAGS), issued just prior to the June 1990 policy,
should enhance a PRP's ability to conduct and EPA's ability to
oversee PRP-conducted risk assessments. However, the risk
assessment document remains identified with the PRP, and the
public may not consider this document prepared under EPA
oversight the equivalent of a document fully prepared by EPA.
Moreover, oversight can have practical limitations; information
received in the course of EPA's review of its policy indicated
that, in some cases, risk assessments were accepted which,
although satisfactory, were not entirely in a form that EPA
desired. Furthermore, performing oversight poses a significant
burden on limited EPA resources, a burden that is likely to be
greater than where the contractor performing the risk assessment
has been selected by EPA. Therefore, EPA maintains its view that
it is generally preferable for risk assessments to be performed
by the Agency rather than by PRPs.
At the same time, the evaluation suggests that the delays
attributable to PRP risk assessments may not be as great as was
previously believed. In general, PRP risk assessments did not
add significantly more time to the RI/FS process than EPA risk
assessments (although, as noted above, EPA expects that
procedures will be developed to reduce delays in performing EPA
risk assessments). In addition, more detailed risk assessment
guidance has now been issued which may make clearer what is
expected in the document and may reduce to some extent the
difficulty of overseeing PRP risk assessments.
Therefore, EPA believes that in some cases it will be
appropriate to allow PRPs to conduct risk assessments. The
critical factor in making this determination is EPA's past
experience with the individual PRP and its contractor. When EPA
is confident that this factor and the other criteria noted
earlier can be satisfied favorably, EPA's burden of oversight and
likelihood of public concern will be significantly reduced.
These factors must be considered by the Region on a case-by-case
basis. Therefore, the 1990 policy is being revised so as to
allow regional personnel discretion to consider the criteria
outlined earlier in this directive.
If you have any questions about this policy, please contact
Stephen Ells, Acting Cnief, Guidance and Evaluation Branch,
Office of Waste Prograns Enforcement, at (703) 603-8934.

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Notice
The policy and procedures set out in this document are intended
for the guidance of Government personnel. They are not intended,
nor can they be relied upon, to create any rights enforceable by
any party in litigation with the United States. U.S.
Environmental Protection Agency officials may decide to follow
the guidance provided in this document, or act at variance with
the guidance, based on an analysis of site circumstances. The
Agency also reserves the right to change this guidance at any
time without public notice.
cc: Director, Waste Management Division,
Regions I, IV, V, VII
Director, Emergency & Remedial Response Division,
Region II
Director, Hazardous Waste Management Division,
Regions III, VI, VIII, & IX
Director, Hazardous Waste Division,
Region X
Regional Counsel, Regions I-X
Regional CERCIA Branch chiefs, Regions I-X
Regional CERCLA Section Chiefs, Region I-X

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