United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
Directive 9345.1-15FS
August 1993
Inspection Prioritization
Guidance
Office of Emergency and Remedial Response
Hazardous Site Evaluation Division (5204G)
EPA/540/F-93/037
Quick Reference Fact Sheet
The purpose of this fact sheet is .to provide guidance to Environmental Protection Agency (EPA), State, and
contractor staff responsible for conducting Site Inspection Prioritizations (SIPs). Of the 36,000 sites currently in
the Comprehensive Environmental Response, Compensation, and Liability Act Information System (CERCLIS)
inventory, approximately 16,700 have undergone Site Inspections (Sis). Of those, however, over 6,000 sites still
require final site disposition decisions (Figure 1). This backlog has made it difficult for EPA to evaluate sites
efficiently on a worst sites first basis. Consequently, EPA established the SIP to address this backlog and to make
decisions on these sites.
Figure 1
SITE INSPECTION PRIORITIZATION BACKLOG
Regional Breakdown
1.400
, 1.200
) 1.000
i ftOO
I 800
• 400
' 900
0
B
v vi vn
REGION
Data as of 5/7/83
BACKGROUND
The Superfund Amendments and Reauthorization Act
(SARA) of 1986 required that EPA revise the Hazard
Ranking System (HRS), the primary mechanism used
to list sites on the National Priorities List (NPL). In
December 1990, EPA promulgated and published the
revised HRS in the Federal Register (55 FR 51532),
superseding the original HRS. During a period of
transition to the revised HRS, sites were evaluated
through the SI stage under the original HRS;
however, EPA felt it would be preferable to make
final site disposition decisions on these sites after
revising the HRS. Information for these sites needs
to be updated to evaluate the site using the revised
HRS. A final decision may be to list the site on the
NPL, make a Site Evaluation Accomplished (SEA)
determination, or defer the site to another Federal
authority (e.g. Resource Conservation and Recovery
Act (RCRA) or Nuclear Regulatory Commission
(NRC)). An SEA decision means that, based on
currently available information, the site does not meet
the criteria for inclusion on the NPL and Federally
funded remediation. Sites designated SEA are
subsequently referred to the appropriate State agency
for any further action.
The goal of the SIP is to gather any additional
information necessary, following the completion of
the SI, to help set priorities among these sites for
NPL listing or to screen them from further Superfund
attention. At a minimum, this would generally
require gathering data to update the site evaluation
and determining whether the HRS score is greater
than 28.5. Typical SIP data gathering efforts may
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include collecting additional site information (e.g.
historical use) and "target" information (e.g., wells
within 4 miles, surface water intakes, fisheries and
sensitive environments within 15 miles downstream).
SIPs may also entail collecting limited samples if this
is required to make a screening decision. The
number of samples for an SIP should range from a
few up to the normal number typically collected for
an SI. An SIP should rarely result in the need for
further investigation through the Expanded Site
Inspection (ESI) stage. ESIs should be reserved for
those sites clearly headed for the NPL and where
significant fieldwork (e.g., well installation or
extensive air monitoring) or other non-routine data
collection activities are necessary.
The SIP is a temporary, intermediate step in the Site
Assessment program to update old Sis and make
screening decisions on a discrete universe of sites
using minimal resources. Therefore funding for SIP
activities is expected to be available for the next two
to four years. The SIP backlog should not continue
to grow. Current Preliminary Assessments (PAs) and
Sis are being completed according to guidance
developed for the revised HRS (see Guidance for
Performing Preliminary Assessments Under CERCLA,
OSWER Directive 9345.1-01A, September 1991 and
Guidance for Performing Site Inspections Under
CERCLA, OSWER Directive 9345.1-05, September
1992). The updated guidance documents recommend
the use of intermediate scoring tools (PA Scoresheets,
PA-Score, and SI Worksheets) to make screening
decisions using site information normally available at
the PA and SI stages. These scoring tools typically
require less site information and effort to make a
screening decision than using PREscore. At the SIP
stage the majority of sites should be scored using SI
Worksheets at a minimum; however, the decision of
which scoring tool (PA Scoresheets, PA-Score, SI
Worksheets, or PREscore) to use for SIPs will be
made on a site by site basis.
REVISED HRS REQUIREMENTS
EPA revised the HRS to comply with the
requirements set forth by SARA. To better assess
the relative degree of risk to human health and the
environment, EPA modified the approach for
evaluating the ground water, surface water, and air
migration pathways that were addressed in the
original HRS and incorporated a direct exposure
pathway (soil exposure) into the composite score used
to evaluate sites. In general, the HRS score reflects
the risk associated with each pathway by estimating:
(1) the likelihood of a release of hazardous
substances; (2) the quantity and toxicity or other
harmful characteristics of on-site wastes; and (3) the
risk to both human and environmental targets.
The revised HRS requires more data than the original
HRS to evaluate a site. The revised HRS evaluates
ground water discharge to surface water, human food
chain exposure, soil exposure, and the potential for
air release. In addition, the evaluation of risk to
ecosystems or environmental targets is broader in the
revised HRS than the original HRS, and the
calculation of waste quantity is more comprehensive.
However, the most crucial information that will need
updating for an SIP is the target data. Table 1
presents a comparison of target needs between the
original and the revised HRS models and identifies
what information might be missing in old Sis.
SIP UNIVERSE
In general, an SIP should be assigned for non-Federal
facility sites which had Sis completed prior to the
implementation of the revised HRS and have not
received a final NPL decision. SIPs are appropriate
where more information is necessary to determine
whether a site should be screened out (designated
SEA or deferred to another Federal authority), or
investigated further for probable inclusion on the
NPL. The extent of additional information required
to make this final decision and the probability of NPL
listing are both important in determining whether an
SIP or an ESI is appropriate. SIP candidates are sites
with an SI completion date entered into CERCLIS
prior to the implementation of the revised HRS (i.e.,
August 1, 1992) and may include: (1) sites without
an event qualifier (i.e., high priority, low priority,
SEA, or deferred), or (2) sites with an event qualifier
of high or low priority.
Sites may not have event qualifiers due to CERCLIS
coding errors. The Region should review file
information for these sites to determine whether a
decision is possible. Sufficient information may be
available to screen out the site from further CERCLA
investigation (SEA or defer to another Federal
authority). The appropriate event qualifier should
then be entered into CERCLIS. If additional
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Table 1: Original vs. Revised HRS Target Data Requirements
PATHWAY
ORIGINAL HRS
TARGETS
REVISED HRS
TARGETS
Ground Water Migration
Pathway
• Ground water use
• Distance to the nearest
well/population served within 3
miles
Distance from a source to the nearest drinking water well
Population served by drinking water wells within four
miles
Apportioned population for blended systems
Resources
Wellhead protection areas
Surface Water Migration
Pathway
Overland/Flood
Migration Component
• Surface water use
• Distance to the nearest intake/
population served
• Distance to sensitive environment
Drinking Water Threat:
• Distance to nearest drinking water intake
• Average flow (cubic feet per second)
• Population served by drinking water drawn by intakes
along the surface water migration pathway within 15
downstream miles
• Apportioned population for blended systems
• Resources
Human Food Chain Threat:
• Location of fisheries
• Annual harvest (in pounds) of human food chain organisms
Environmental Threat:
• Location of sensitive environments
• Wetlands frontage length (in miles)
Ground Water to Surface
Water Migration
Component
NA
Same as above
New component to the surface water pathway. If both the
overland/flood and the ground water to surface water
components are scored, the greater of the two component
scores is selected.
Soil Exposure Pathway
NA
The original HRS included a direct
contact pathway, but that pathway
was not calculated in the overall
HRS migration score.
Resident Population Threat:
• Number of individuals who live, work, attend school or
day care within property boundaries and within 200 feet of
observed contamination
• Location of terrestrial sensitive environments within the
area of observed contamination
• Resources
Nearby Population Threat:
• Number of individuals who live or attend school within a
one-mile travel distance from any source with observed
contamination
• Attractiveness/accessibility of sources
Air Migration Pathway
Land use
Population within four miles
Distance to sensitive
environments
Distance from an emission source to the nearest individual
Population within a four-mile radius of sources
Resources within one-half mile of sources
Distance from sources to sensitive environments within
four miles of sources
Total wetland acreage within four miles of sources
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information is required to make a final decision,
either a high priority or low priority recommendation
should be entered as the event qualifier (Regional
guidance should be consulted to distinguish between
high and low priority recommendations). These sites
would then fall into the second category of sites.
Sites with high or low priority event qualifiers may
still require additional data, either desktop or
analytical, to support a revised HRS score. Since the
average level of effort per SIP is 190 hours, sites
which require significantly more effort to support a
final decision (> 550 hours) may not be appropriate
for an SIP assignment. If a greater level of effort is
required to fill SI data gaps and to support a final
decision, particularly if the site is likely to be listed
on the NPL, then an ESI may be more appropriate.
In general, an ESI should be assigned if extensive
fieldwork or unusual data collection activities are
required prior to preparing an NPL package. Factors
that should be examined to help determine whether an
SIP or an ESI should be assigned are provided in
Table 2. In addition to sites with and without SI
event qualifiers, there may be other sites evaluated
under the original HRS which need further evaluation
via the SIP. This includes sites where an incorrect
site decision was made or new file information is
made available which might significantly alter the
HRS evaluation of the site. The decision as to
whether an SIP is appropriate for these sites will be
made on a case by case basis. Note, however, that
these sites are not included as part of the SIP backlog
(Figure 1) because site decisions have already been
entered into CERCLIS.
SETTING PRIORITIES
Figure 1 shows that some Regions have a very large
SIP backlog and may need to incorporate additional
measures to set priorities among their SIP candidates.
One method may be to identify sites located in
vulnerable geographic areas. Features that may
characterize an area as vulnerable include: population
density, geologic and hydrogeologic features, surface
water intakes, fisheries, municipal drinking water
wells, wetlands, and other considerations. Much of
this information is available in existing databases that
can be incorporated into a Regional geographic
information system (GIS). By plotting these features,
sites located in vulnerable areas could then be
identified.
The issue of setting priorities is not limited to SIPs.
If further investigation is warranted at the conclusion
of an SIP, these sites, which are now ESI candidates,
must also be prioritized. It is critical to set priorities
for ESI candidates, not only to comply with EPA's
policy of assessing the worst sites first, but also to
allow for the efficient use of limited resources. ESIs
consume an average of 1,000 hours; therefore
Regions must set priorities for ESI candidates while
keeping in mind their budgetary constraints. Regions
may use more detailed prioritization schemes to
further identify ESI candidates.
Regions are encouraged to investigate their Regional
GIS capabilities as well as other prioritization
methods, not only to address the SIP backlog, but
also to help direct other environmental protection
efforts on a worst sites first basis.
Table 2: Factors to Determine SIP or ESI Assignment
SIP
Limited data are necessary to determine whether or
not the site will attain a score greater than the cutoff
score for NPL eligibility
NPL eligibility is uncertain
SI completed but no HRS score calculated
SI completed but preliminary HRS scoring assumes
primary targets without sample results
ESI
Substantial data collection is necessary to prepare NPL quality
HRS package (>550 hours)
Probable NPL site
SI score (completed with SI Worksheets) is greater than the cutoff
score for NPL eligibility
SI sampling has verified contamination at primary targets; site
score is greater than the cutoff score for NPL eligibility
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SIPS and SACM
The Superfund Accelerated Cleanup Model (SACM)
requires better integration of all Superfund program
components to make cleanups more timely and
efficient. During an SIP, activities should be
coordinated to ensure that data collected support
assessment, enforcement, and response activities.
The Regional Decision Team (RDT), which is
responsible for making site decisions to ensure early
risk reduction, will establish the strategy for
addressing sites. SIP data collection efforts should be
consistent with these strategy decisions.
The basic principles of SACM assessment are built
upon the need to eliminate redundancy and expedite
the Superfund process. SIPs will help identify
priority sites so that EPA resources are expended on
sites that require prompt risk reduction. For further
information, refer to Assessing Sites Under SACM -
Interim Guidance OSWER Directive 9203.1-051,
December 1992.
SIP ACTIVITIES
Activities to be conducted for an SIP will depend on
the additional information necessary to update the old
SI in accordance with current guidance and the
revised HRS. In all cases, however, site information
must be reexamined to update current site conditions,
satisfy revised HRS requirements, and identify the
potential need for removal actions (see the next
section for further information on identifying
potential removal actions during SIPs).
Because activities necessary for SIPs will vary due to
the quality and comprehensiveness of site information
that is available, three levels have been identified to
meet the goal of an SIP as illustrated in Table 3.
It is estimated that each SIP will require at least
updated HRS scoring; two-thirds will require desktop
data collection and updated scoring; and one-third
will require desktop data collection, updated scoring,
and limited sampling. It is estimated that an SIP will
average 190 hours per site. EPA Regional staff will
help determine the level of effort necessary for each
SIP assigned. The choice of which HRS scoring tool
to use (PA Scoresheets, PA-Score, SI Worksheets, or
PREscore) will depend on the amount of information
available for the site. At a minimum, revised HRS
scores must support each SIP decision. Sites with
revised HRS scores below the cutoff (28.5) are
screened out, and will receive an SEA decision in
CERCLIS. Sites with revised HRS scores above the
cutoff will be recommended for either an ESI (if
extensive information/data collection is still required)
or for a full HRS package.
Level A: The first step in conducting an SIP is to
generate a revised HRS score. This typically
requires collecting new target information for the
revised HRS target distance limits (see Table 1).
This first activity is necessary for all SIPs to generate
a site score according to the revised HRS, identify
data gaps, and determine whether additional SIP
activities (desktop data collection and/or sampling)
are necessary to make a final site disposition
decision. If desktop data collection and sampling are
not necessary, the site's revised HRS score should be
documented with these new target data incorporated,
and a final site disposition decision should be entered
into CERCLIS.
Level B: Most SIPs will likely require the collection
of additional site specific desktop data beyond
Table 3: SIP Levels versus SIP Activities
SIP LEVEL
LEVEL A
LEVEL B
LEVEL C
SIP ACTIVITIES
• Updated (revised HRS) scoring
• Updated (revised HRS) scoring
• Desktop data collection
• Updated (revised HRS) scoring
• Desktop data collection
• Limited Sampling
APPROXIMATE
TOTAL HOURS
40-60
80- 100
350 - 550
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updating a site's target information. Level B SIPs
typically include researching and updating site
information because site conditions may have changed
significantly since the completion of the old SI. All
appropriate data sources (EPA, State, municipal, etc.)
should be researched to ensure that information is
updated for the SIP. The SI Data Summary
(Appendix B of the Guidance for Performing Site
Inspections Under CERCLA) and the Site Assessment
Information Directory (SAID) may be useful data
collection tools for this task. After this new
information is collected, the site's revised HRS score
should be documented incorporating this new data,
and a final site disposition decision should be entered
into CERCLIS.
Level C: It is estimated that approximately one-third
of SIPs will require sampling activities in addition to
the activities described for Level A or B SIPs. EPA
Regional staff will determine the appropriate
sampling strategies necessary for Level C SIPs.
After sampling activities are conducted, the site's
revised HRS score should be documented
incorporating the new analytical data, and a final site
disposition decision should be entered into CERCLIS.
Site visits may be necessary for Level A, B, or C
SIPs to verify and update site conditions, evaluate the
need for a potential removal action, identify target
information for HRS scoring, and/or conduct
sampling activities. As a cost savings measure,
Regions should consider scheduling SIPs in
geographic clusters so that site visits can be
combined. SIP field activities may also be combined
with other Site Assessment and integrated assessment
field activities.
SIP products will depend on what activities are
conducted and will be determined by EPA Regional
staff. For example, the final product for an SIP
requiring only Level A activities may consist of a
brief memo updating site and target information along
with completed revised HRS scoresheets. Products
for an SIP requiring Level B or C activities may
consist of a full report, similar to the SI reporting
format, along with completed HRS scoresheets.
SIPs will be tracked in CERCLIS as a subevent of
the SI. Refer to the sidebar for the appropriate
CERCLIS entry protocols.
CERCLIS Data Entry for SIPs
• Enter the SIP as a subevent (SP) to the
last SI.
• The completion date is the date the report
is accepted by the Region and a
disposition (event qualifier) is made on
the report.
• Replace the last SI event qualifier with
the new SIP event qualifier (Higher,
Lower, Deferred, or SEA).
Only sites where the last SI completion date is
prior to August 1, 1992 are eligible for SIPs.
Sites with SI qualifier "N" or "D" are not
eligible for SIPs unless new information
relevant to the decision becomes available.
IDENTIFYING POTENTIAL REMOVAL
ACTIONS DURING SIPs
SIP field activities can be very useful in identifying
sites where a potential removal action may be
necessary. Removals are relatively short-term
actions, compared to the long-term remedial solutions
that the NPL addresses. Removal actions are
designed to respond to situations that require
immediate action to eliminate a present threat or to
avoid a more serious future problem (for example,
containing leaking drums of hazardous substances to
prevent ground water contamination). Removal
actions can be of an emergency, time-critical, or non-
time-critical nature and can include, but are not
limited to, any of the following (see Superfund
Removal Procedures, OSWER Directive 9360.3-01,
February 1988):
• Fencing the site
• Providing 24 hour security to restrict public
access
• Stabilizing waste sources such as leaking
drums or overflowing surface
impoundments
• Physical removal of hazardous substances
• Capping areas of obvious contamination
• Assessing the need to temporarily relocate
populations
• Providing alternative drinking water
supplies
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Table 4 outlines the factors that EPA considers in
determining the appropriateness of a removal action
pursuant to section 300.415(b) of the National Oil
and Hazardous Substances Pollution Contingency
Plan, commonly known as the NCP (40 CFR Part
300).
Under the revised HRS, waste removals may be
considered for HRS scoring purposes under certain
circumstances. For more information concerning the
requirements for considering removal actions, refer
to The Revised Hazard Ranking System: Evaluating
Sites After Waste Removals, OSWER Directive
9345.1-03FS, October 1991.
SIP SAMPLING
Because SIPs that include sampling will require
significantly more hours, some analysis should be
conducted to determine if sampling is critical for
making a final decision. For example, if a
preliminary site score is 28.5 or greater, all targets
for which actual contamination (level I and II) is
suspected should be identified. By examining various
scoring scenarios, the site score should be tested to
determine whether the site score will fall below the
28.5 cutoff for NPL eligibility if the targets with
suspected actual contamination are scored as
potentially contaminated. If the site score falls below
28.5 with this modification, sampling is necessary to
verify the suspected contamination of the target
receptors. If the site score remains 28.5 or greater,
sampling may not be necessary. On the rare occasion
where an SIP results in the need for further
investigation via an ESI, new data obtained from
samples collected for the SIP may help set priorities
for sites needing further work.
For additional information concerning sampling
guidance for the revised HRS requirements, refer to
Guidance for Performing Site Inspections Under
CERCLA, OSWER Directive 9345.1-05 and the
Hazard Ranking System Guidance Manual, OSWER
Directive 9345.1-07.
In summary, the goal of the SIP is to gather any
additional information necessary, following the
completion of the SI, to make decisions on this
discrete universe of sites. Activities conducted for an
SIP should be consistent with current guidance,
including SACM, and should result in sites being
either removed from further Superfund attention or
recommended for NPL package preparation.
EPA developed the SIP as a cost effective,
intermediate step in the Site Assessment process to
screen out less serious problems and expedite action
at sites that require additional Superfund response.
Site priorities must continue to be set on a worst first
basis to ensure that Superfund cleanups are timely
and efficient.
Table 4: Removal Action Criteria
1 Actual or potential exposure to nearby human populations, animals, or the food chain from hazardous substances
or pollutants or contaminants;
2. Actual or potential contamination of drinking water supplies or sensitive ecosystems;
3. Hazardous substances or pollutants or contaminants in drums, barrels, tanks, or other bulk storage containers,
that may pose a threat of release;
4 High levels of hazardous substances or pollutants or contaminants in soils largely at or near the surface, that
may migrate;
5 Weather conditions that may cause hazardous substances or pollutants or contaminants to migrate or be released;
6. Threat of fire or explosion;
7. The availability of other appropriate Federal or State response mechanisms to respond to the release; and
8. Other situations or factors that may pose threats to public health or welfare or the environment.
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REFERENCES
U S Environmental Protection Agency, 1988. Superfund Removal Procedures, OSWER Directive 9360.3-01.
U.S. Environmental Protection Agency, 1990. Hazard Ranking System, Final Rule, 55 FR 51532, December 14,
1990.
U.S. Environmental Protection Agency, 1990. National Oil and Hazardous Substances Pollution Contingency Plan.
40 CFR Part 300. 55 FR 8666, March 8, 1990.
U.S. Environmental Protection Agency, 1991. Guidance for Performing Preliminary Assessments Under
CERCLA, OSWER Directive 9345.0-01A.
U.S. Environmental Protection Agency, 1991. Revised Hazard Ranking System: Evaluating Sites After Waste
Removals, OSWER Directive 9345.1-03FS. ,. I0ft,
U S Environmental Protection Agency, 1991. Site Assessment Information Directory (SAID), October 31, 1991.
u!s. Environmental Protection Agency, 1992. Assessing Sites Under SACM-Interim Guidance, OSWER
Directive 9203.1-051. . n™~i A
U.S. Environmental Protection Agency, 1992. Guidance for Performing Site Inspections Under CERCLA,
OSWER Directive 9345 1-05
U.S. Environmental Protection Agency, 1992. Hazard Ranking System Guidance Manual, OSWER Directive
9345.1-07. _
Additional copies can be obtained from:
D..UU- P.PA Employees
Public •*" muyivjww /rTV-rv
National Technical Information Service (NTIS) or Superfund Documents Center (SDC)
US Department of Commerce U.S. Environmental Protection Agency
5285 Port Royal Road «>1 M Street, SW (OS-245)
Sorinfffield VA 22161 Washington, DC 20460
CHSwSaO (202^260^760 or (202) 260-2596 (FAX)
Order f: PB93-963340
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