EPA 510-R-00-002
Project Contacts
Richard Mattick,
USEPA/OUST
703/603-7154
Mattick.Richard@epa.gov
John Connor, GSI
713/522-6300 ' '
jaconnor@gsi-net.com
Scott Murphy, ASTM
610/832-9685
smurphy@astra.org
State and Regional Contacts
Gilberto Alvarez, USEPA Region 5
Chicago, Illinois
David Ariail, USEPA Region 4
Atlanta, Georgia
ChetClarke,TNR.CC
Austin, Texas
Douglas Clay, Illinois EPA
Springfield, Illinois
Lynn Dail, USEPA Region 6
Dallas, Texas
Alan Hancock, USEPA Region 7
Kansas City, Kansas
James Humeston, Iowa DNR
Des Moines, Iowa
Ruth Strauss, NC DENR
Raleigh, North Carolina
Jo Taylor, USEPA Region 8
Denver, Colorado
PaulZahn, Utah DEQ
Salt Lake City, Utah
fcPROV^
Risk-Based Decision Making
Performance Assessment Study
Bulletin #2
Study Results and Recommendations for
RBDM Program Performance Monitoring
Practical measures have been developed for evaluating the impact of Risk-
Based Decision Making (RBDM) on state underground storage tank corrective
action programs. These measures have been used to evaluate the effect of
RBDM on the corrective action programs of five pilot states. In a majority of the
pilot states, implementation of an RBDM program resulted in an increase in case
closures and a decrease or stabilization in case backlog. Additional findings
indicate that these RBDM programs successfully targeted low-risk sites for
closure while retaining higher-risk sites for further action. Minor modifications to
state program databases will allow for a more detailed evaluation of program
performance measures.
This document has been funded
wholly by USEPA under assistance
agreement X825708-01. The infor-
mation may not necessarily reflect the
view of the Agency, and no official
endorsement should be inferred.
Introduction
The Risk-Based Decision Making
(RBDM) Performance Assessment
Study has been conducted as a
research effort designed to assist
state and territorial environmental
regulatory agencies with the
evaluation of their individual
RBDM programs for Under-
ground Storage Tanks (USTs).
The specific goals of this study
were to: i) develop practical,
quantitative measures for evalu-
ating the impact of RBDM on
achieving state agency manage-
ment goals, ii) apply these meas-
ures to five state RBDM programs
to evaluate program performance,
and iii) provide general guidelines
for other state and territorial envi-
ronmental agencies interested in
tracking the performance of their
RBDM programs.
This Bulletin reviews the proce-
dures and results of this RBDM
Performance Study and presents
guidelines for monitoring and
evaluating the effectiveness of
RBDM programs. In addition,
self-reported evaluations of two
other state programs are included.
The study was funded by the
United States Environmental
Protection Agency (USEPA) Office
of Underground Storage Tanks
(OUST) under Assistance Agree-
ment #X825708-01 to the Ameri-
can Society for Testing and Mate-
rials (ASTM). Groundwater
Services, Inc. (GSI), of Houston,
Texas, has conducted the study.
The results have been reviewed
by the participating states, USEPA
regions, USEPA OUST, and by
Partnership in RBCA Implemen-
tation (PIRI).
Risk-Based Decision Making
The USEPA Office of Solid Waste
and Emergency Response
(OSWER) Directive 9610.17 en-
courages all state UST programs
to apply RBDM to the corrective
action process at petroleum re-
lease sites. RBDM is a flexible de-
cision management framework
that is customized to fit the needs
of individual agency programs.
When applied to the UST correc-
tive action process, RBDM may
also be referred to as Risk-Based
Corrective Action or "RBCA".
The ASTM RBCA Standard E-
1739-95 is one example of an
RBDM framework that has been
used by states to design or
March 2000
RBDM Performance Assessment Bulletin #2
Page 1 of 11
-------
ILLINOIS ENVIRONMENTAL
PflOTECTlON AGENCY
IOWA DEPARMENT
OF NATURAL RESOURCES
NCDENR
TEXAS NATURAL RESOURCE
CONSERVATION COMtSSlON
augment their corrective
action programs. An
RBDM program typically
includes three principal
activities:
Risk-Based Site Prioritization: Pri-
oritize sites based on the timing
or magnitude of potential im-
pacts to human health and the
environment.
Site-Specific, Risk-Based Remedia-
tion Goals: Determine risk-based
concentration limits for affected
environmental media designed
to prevent impacts on human
health and the environment.
Tier 1 remediation goals repre-
sent generic concentration limits,
based on conservative default
assumptions. Tier 2 and Tier 3
provide site-specific media
cleanup limits based on addi-
tional site data and more sophis-
ticated data analysis.
Remedy Selection: Select remedia-
tion alternatives, such as re-
moval or exposure control, to
address site-specific risk drivers.
RBDM is a science-based process
that offers a clearly defined and
consistent basis for site evaluation
and remediation. As a result, im-
plementation of RBDM corrective
action programs is expected to
result in increased program effi-
ciency and improved risk reduc-
tion.
RBDM Performance
Assessment Study Background
Five state environmental regula-
tory agencies have participated in
this preliminary study to evaluate
the effectiveness of their RBDM
programs:
Illinois: Illinois Environmental
Protection Agency, Leaking Un-
derground Storage Tank Section
Iowa: Iowa Department of
Natural Resources, Under-
ground Storage Tank Section
North Carolina: North Carolina
Department of Environment
and Natural Resources,
Groundwater Section
Texas: Texas Natural Resource
Conservation Commission,
Remediation Division
Utah: Utah Department of Envi-
ronmental Quality, Division of
Environmental Response and
Remediation .
Each of the selected pilot states
has implemented a state RBDM
program and expressed interest in
evaluating their program per-
formance. To provide geographi-
cal balance, no more then one
state per USEPA Region was se-
lected for this study. In addition
to the five pilot states, this bulletin
summarizes the program per-
formance of two states, Michigan
and Alabama, which have evalu-
ated the impact of their RBDM
programs independent of this
study.
For this study, the pilot states
provided input on their individ-
ual program goals, the perform-
ance measures currently utilized
in their state, and the utility and
feasibility of the RBDM perform-
ance criteria developed for this
study. In addition, each pilot state
provided program performance
data in the form of program data-
bases, and assisted with internal
program evaluations and inter-
pretations of study results.
RBDM Program Goal and
Performance Measures
The overall goal of state UST pro-
grams is to protect human health
and the environment from re-
leases associated with leaking un-
derground storage tank (LUST)
sites. In order to achieve this goal,
March 2000
RBDM Performance Assessment Bulletin #2
Page 2 of 11
-------
the RBDM programs imple-
mented by the pilot states ad-
dressed in this study shared the
following objectives:
Risk Reduction: Reduce the
human health and ecological
risks associated with LUST sites.
Expedited Site Evaluation,
Remediation, and Closure:
Streamline the site assessment
process to close sites which do
not pose an unacceptable risk to
human health or the environ-
ment and expedite the remedia-
tion of sites with unacceptable
risks.
Cost Control/Resource Allocation:
Reduce the cost of site remedia-
tion and closure without com-
promising protection of human-
health and the environment. Fo-
cus available resources on high-
risk sites. Reduce the adminis-
trative cost of program man-
agement.
TABLE 1: LIST OF SUGGESTED PERFORMANCE MEASURES FOR
EVALUATION OF LUST RBDM PROGRAMS
PROGRAM
GOAL
Risk
Reduction
Expedited
Evaluation,
Remediation,
Closure
Cost
Control/
Resource
Allocation
PERFORMANCE
MEASURE
Composite Site
Classification
Profile
(see Figure 3)
?/-V Sf £»/ ig3***~ *
Compojife
CorfeflfuentKS-
&T 4.**" Ji -?1"?
Cleanup
Completed
alog
No Action Sites
Time to Action
Plan Approval
Remediation
Cost
TRACKING DESCRIPTION
Distribution of risk-based
site classification ratings or
sum of site classification
scores through time
Number of corrective ac-
tions resulting in case clo-
sure
urfirieijpf sites currently*"
anaeed by Ihe state j
~ *~ *.** ^0. sfeSf A-0* -^
^ *" "
Percentage and overall
number of sites not
requiring corrective action
following risk-based site
pjreiall^ ^f
evaluation
Percente
Subs? 0
Time from incident report-
ing to state approval of a
corrective action plan
Deporting w"Hje_c|pstire
e
Total expense from incident
reporting to case closure for
the responsible party or for
the state reimbursement
fund
SITE DATA REQUIRED
Initial site classification,
Current site classification,
Site score (i.e., high score
for high risk)
Ooiuredate
L -
Closure date,
Basis for closure
notice,^ t- ' j
ipnT?lan approval Sate
Incident reporting date,
Action Plan approval date
I^cidera repoffirtgfdatej"
Site remediation cost
(including assessment and
closure costs),
Remediation cost
reimbursed by state fund
March 2000
RBDM Performance Assessment Bulletin #2
Page 3 of 11
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To assist states in evaluating the
benefits of their RBDM programs,
this study has identified quantita-
tive performance measures that
correspond to each of the three
common RBDM program goals
(see Table 1). By tracking these
parameters over time for their
LUST site population, states can
measure progress with regard to
risk reduction, expedited site
evaluation, remediation, closure,
and cost control.
The suggested performance
measures should be viewed as a
menu of options, from which each
regulatory authority can select the
most appropriate measures for
their specific program. These per-
formance measures are described
in more detail in the prior Per-
formance Assessment Study Bul-
letin #1 issued in March 1999
(ASTM, 1999). To determine the
impact of RBDM implementation
on program performance, these
measures have been used to
evaluate program performance
based on data available from each
of the pilot states.
Evaluation of Pilot State
Programs: Findings and
Implications
The five pilot states each maintain
a database of all active and closed
LUST sites which have been en-
tered into the regulatory process
for site remediation. GSI reviewed
each database to identify pa-
rameters which could be used to
evaluate progress toward RBDM
program goals. The pilot states
implemented RBDM for their cor-
rective action programs between
1994 and 1998 (see Table 2). In
order to compare program per-
formance before and after RBDM
implementation, performance has
been evaluated for the period of
1990 to 1999.
The results of this study support
the following general findings
with regard to the common pro-
gram management goals:
Expedited Site Evaluation,
Remediation, and Closure: Im-
mediately following imple-
mentation, of their RBDM pro-
gram, 4 of the 5 pilot states ob-
served a dramatic spike in case
closures per year and a stabili-
zation or decrease in case back-
log. In general, the average case
age at time of closure increased
following RBDM implementa-
tion. Combined with the in-
crease in case closures, this
finding indicates that many
older cases which have been in
the regulatory process for many
years are now being addressed.
The observed reduction in case
backlog is likely to reduce the
administrative burden for the
regulatory agency, allowing a
more efficient allocation of
available resources.
In the first year of the Utah
RBCA Tier 1 program (1995), the
number of case closures in-
creased by 120%, indicating that
a Tier 1 process of generic
screening criteria can signifi-
cantly impact program per-
formance (see Figure 1). Fol-
lowing implementation of a
RBDM-based corrective action
program in Iowa, 77% of RBCA
Tier 1 site assessment
reports approved by the DNR
resulted in case closure and 28%
of Tier 2 site assessments re-
sulted in case closure, indicating
that the RBDM process has been
effective at identifying sites for
closure or remediation. Key re-
sults for individual pilot states
are summarized in Table 2.
Risk Reduction: Available in-
formation regarding risk-based
site classification (Texas and
North Carolina) indicates that
most of the LUST site cases
March 2000
RBDM Performance Assessment Bulletin #2
Page 4 of 11
-------
800
Utah LUST Case Closures Per Year
1990 1991 1992 1993 1994 1995 1996 1997 1998*
Year
'* = 1998 data is through 10/1/98.
FIGURE 1: EFFECT OF RBDM ON LUST CASE CLOSURES IN UTAH
8000,
Texas LUST Case Backlog
7000.
6000.
5000,
4000.
3000.
2000.
1000.
o High-Risk Sites
Low-Risk Sites
,RBCA,
Exit Criteria -
1990 1991 1992 1993 1994 . 1995 1996 1997 19:
Year
North Carolina LUST Case Backlog
1990 1991 1992 1993 1994 1995 1996 1997 199B 1999
FIGURE 2: EFFECT OF RBDM ON LUST CASE BACKLOG
IN TEXAS AND NORTH CAROLINA
March 2000
RBDM Performance Assessment Bulletin #2
Page 5 of 11
-------
' !| |,.,!"'||||f ,'' .fl1!1 " ., " , l,"l"'1i I'll!
closed by these state RBDM
programs are low-risk sites (see
Figure 2). These examples dem-
onstrate that RBDM programs
are effectively meeting the state
program objective of closing
low-risk cases while retaining
higher-risk cases in the regula-
tory process for further evalua-
tion or remediation. The re-
duced backlog of low-risk sites
should allow available resources
to be more effectively targeted
to the higher-risk sites.
Cost Control/Resource Alloca-
tion: Cost data in the LUST site
databases provided by the pilot
states were not sufficient to
measure the cost impacts of
RBDM at this time. However,
the significant reductions in case
backlog reported by some states
clearly corresponds to reduced
program costs.
An internal cost survey was
conducted by the Texas Natural
Resource Conservation Com-
mission to determine the impact
of RBCA implementation on the
cost of site remediation. Be-
tween 1994 and 1998, remedia-
tion/closure costs were reduced
by 70% for soil-only sites (me-
dian cost reduced to
$24,000/site from $80,000/site),
and by 58% for low-risk
groundwater impact sites (me-
dian cost reduced to $107,000
from$250,000/site).
Potential Confounding Factors
Interpretation of the impact of
RBDM on program performance
may be complicated by con-
founding factors such as the 1998
upgrade deadline, changes in
staffing at state regulatory agen-
cies, or changes in state funding of
site remediation. These factors
can also impact the program
measures designed to measure the
effectiveness of RBDM. To control
for these confounding factors, the
impact of the RBDM on program
performance independent of con-
founding factors is best under-
stood through the evaluation of
multiple performance measures
which cover all of the RBDM pro-
gram objectives.
Results from Other States
In addition to the five states
evaluated for this study, Michigan
and Alabama have independently
evaluated the performance of
their LUST management pro-
grams following the implementa-
tion of RBDM. Alabama Depart-
ment of Environmental Manage-
ment (DEM), UST Corrective Ac-
tion Unit implemented an RBDM
program in April 1998 and is cur-
rently tracking performance. In
the first year of the program, Ala-
bama DEM saw a reduction of 106
active cases classified as low-risk
sites and a corresponding increase
of 115 closed cases (4% of the ac-
tive'case population). Although
recently implemented, the Ala-
bama RBDM program appears to
be successful in closing low-risk
sites (Malaier, 2000).
Michigan Department of Envi-
ronmental Quality (DEQ), Storage
Tank Division implemented an
RBDM program in April 1995. In
1996, Michigan DEQ reported a
61% increase in LUST case clo-
sures compared to the average
case closure rate for 1990 to 1995.
In addition, Michigan DEQ
achieved a 30% decrease in case
backlog from 1995 to 1998. Im-
plementation of the RBDM pro-
gram resulted in a 24% average
reduction in remediation/closure
costs for UST sites, representing a
$39,000 cost savings per site
(Michigan DEQ, 1996).
March 2000
RBDM Performance Assessment Bulletin #2
Page 6 of 11
-------
TABLE 2. RESULTS FOR PILOT STATE RBDM PROGRAM
PERFORMANCE EVALUATION
A »f ~- '
*STATB/AGENCX>
'< f % "jf/fl
Texas Natural
Resource ^
Conservation* *£,
Commission, ?
Remediation
\crier; > 5
Department of
Environmental)
Duality, Division '
of Environmental
Response ^nd
Remediation'' / '
1 "V **
North Carolina
'Department of!
Environment
Resources, >'
* Gg*ttj»djwaier Sec-
Jtoa. ,
Ibfaa "L ; x
Department
Resources;''"'''*''*/ *
Underground "^ -«
-Storage Tank ^
*Sechon '- . ,. ,
Illinois
Hlrrfois*
p ferff ^X^
'leaking-^
^Storage Tank. ^ ^
^Section - '
RBDM
PROGRAM
IMPLEMEN-
TATION
Risk-Based
Corrective Action
for Leaking Stor-
age Tank Sites,
January 1994.
Exit Criteria,
September 1997.
Risk-Based
Corrective Action
Tier 1, September
1995.
Risk-Based
Corrective
Action
Tier 2, June 1998.
Risk-Based
Corrective Action
for UST sites,
January 1998.
Risk-Based
Corrective
Action, January
1997.
Tiered Approach
to Corrective
Action Objectives,
January 1997.
DATABASE
Responsible
Party
Remediation
Database
Leaking :
Under-
ground
Storage Tank
Database
Incident
Management
Database
UST/LUST
Database
Leaking
Under-
ground
Storage Tank
Database
PERFORMANCE MEASURES
LUST SITE
REMEDIATION/
CLOSURE
46% increase
in case closures
1996 to 1997.
31% decrease
in case backlog
1994 to 1998.
120% increase
in case closures
1994 to 1995.
53% decrease
in case backlog
1994 to 1998.
46% increase
in case closures
1997 to 1998.
1% decrease
in case backlog
1997 to 1999.
134% increase
in case closures
'94-'96to'97-'99.
14% decrease in
case backlog
1996 to 1999.
8% decrease in
case closures
1996 to 1997.
8% increase in
case backlog
1996 to 1998.
RISK
REDUCTION
Preferential
closure of low-
risk cases,
remediation of
higher-risk
cases.
ID
Preferential
closure of low-
risk Cases,
remediation of
higher-risk
ID
ID
COST CONTROL
58 to 70%
decrease in
remediation
cost for
low-risk soil
or groundwater
sites.
ID
ID
ID
ID
NOTE: ID = Insufficient Data
General Recommendations for
RBDM Performance Monitoring
Evaluation of the pilot state data-
bases shows that most states track
data to provide important infor-
mation on the performance of
their regulatory program with re-
gard to key management objec-
tives. However, additional data
that would allow for a more com-
plete assessment of program per-
formance was often available in
individual site reports but was not
recorded electronically. In many
cases, minor modifications of da-
tabase parameters may be re-
quired to incorporate the quanti-
tative performance measures
identified in this study (see Table
1). Customizing a state program
for the purpose of an RBDM
March 2000
RBDM Performance Assessment Bulletin #2
Page 7 of 11
-------
Yean
Year 2
Years
High \->. Low
Risk Category
High f- Low
Risk Category
High f- Low
RiskCatagory
FIGURE 3: USE OF SITE CLASSIFICATION PROFILE TO TRACK RISK REDUCTION
performance assessment involves
the following steps: i) using the
list provided in Table 1 as a guide,
select or create relevant perform-
ance measures that address key
program objectives; ii) review the
current state database to deter-
mine whether required data is
currently recorded; and iii) mod-
ify the current state database to
include the missing data fields.
The LUST module of "UST Ac-
cess," a database system devel-
oped by the USEPA Office of Un-
derground Storage Tanks (OUST),
is an example of a database that
contains many of the required
data fields and can also be readily
modified or queried for evalua-
tion purposes. For more informa-
tion on UST Access, contact
USEPA OUST at the web address
provided at the end of this bulle-
tin.
In addition to these general
guidelines, results of this pilot
study show that the following
database parameters can signifi-
cantly impact the ability to track
program performance:
1) Basis for Closure: As a sup-
plement to the time to closure
measure, a "Basis for Closure"
field can be used to record the
reason that the case qualified for
closure. Tracking the reason for
case closure would assist in iden-
tifying the types of sites being
managed efficiently under RBDM,
as well as those for which
achieving closure is still difficult.
In addition, this field will allow a
more complete interpertation of
the "time to closure" measure.
To assist in analysis of this per-
formance data, die reason for clo-
sure should be based on defined
categories, such as those listed on
Table 3.
2) Risk Reduction: Surveying the
risk-based site classification of the
LUST site population over time
(as shown on Figure 3) can serve
as a convenient measure of risk-
reduction. If the RBDM program
is effectively reducing risk, the
site classification profile should
reflect a general shift toward low-
risk categories from year to year.
However, to measure risk reduc-
tion, the site classification system
must be based on the magnitude
and immediacy of potential im-
pacts on site receptors, using crite-
ria similar to those employed in
the ASTM RBCA site classification
system (ASTM, 1995). Classifica-
tion systems based on physical
site characteristics (e.g., soil type,
groundwater velocity, chemical
contaminants) do not reflect the
change in risk conditions as
remediation progresses and risks
are mitigated. Furthermore, to
quantify risk reduction, both the
initial and the current risk classifi-
cation must be recorded for each
site. The initial risk classification
remains fixed; however, the cur-
rent risk classification can change
as site remediation progresses.
March 2000
RBDM Performance Assessment Bulletin #2
Page 8 of 11
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TABLE 3. POTENTIAL LUST CASE CLOSURE CATEGORIES
CLOSURE
CATEGORY
No Action
Risk Assessment
Soil Excavation
Monitored Natural
Attenuation
Active Soil Remedy
Active Groundwater
Remedy
DESCRIPTION , ,."...'
K * * ~ r f ! "^ * *="5
Soil and groundwater constituent concentrations are less
than generic screening levels; no remedy or monitoring re-
quired.
Soil and groundwater constituent concentrations are less
than site-specific risk-based standards; no remedy or moni-
toring required.
Site qualified for closure following excavation of affected site
soils.
Site qualified for closure following monitored natural at-
tenuation of affected groundwater.
Site qualified for closure following on-site treatment of soils.
Site qualified for closure following active groundwater reme-
diation.
Using this approach, total risk re-
duction over time for the full
LUST case population can be
quantified as illustrated in Fig-
ure 3.
The site constituent reduction
factor (CRF, the ratio of site con-
centration to site-specific clean-up
standard for specific constituents)
can be used as an additional
measure of site risk reduction
over time. This performance
measure requires that both the
initial and current site concentra-
tions and the applicable site-
specific clean-up standards be re-
corded for key constituents.
However, the CRF may be diffi-
cult to interpret at sites where ex-
posure control remedies are se-
lected.
3) Remediation Cost: Informa-
tion on the cost of site remediation
is typically recorded in a database
separate from the other program
performance data. In addition,
cost data is often limited to reim-
bursed costs for sites eligible for
state funded remediation.
The addition of a "Total Reme-
diation Cost" field to the primary
state database would allow an
analysis of remediation costs for
all sites regulated under the state
corrective action program. This
cost data can be collected by re-
questing an estimated total reme-
diation cost, inclusive of site as-
sessment and response action
costs, as part of the final request
for case closure.
4) Specific Constituents: As
demonstrated by the recent focus
on MTBE at LUST sites, the pres-.
ence of fuel oxygenates in
groundwater may have a signifi-
cant impact on regulatory pro-
gram performance of RBDM. Re-
cording the specific constituents
which exceed remediation goals at
each site could serve to illustrate
the effect of individual constitu-
ents on case closure, remediation
cost, or other performance meas-
ures.
For some states, recording addi-
tional program performance data
in an electronic database may rep-
resent a significant burden in
terms of cost and manpower re-
quired to obtain, validate, and in-
put the data. Clear and simple
guidelines for submittal of re-
quired site reports can serve to
reduce the burden of recording
March 2000
RBDM Performance Assessment Bulletin #2
Page 9 of 11
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program performance data. For
example, standardized reports or
summary forms can provide key
performance data in standardized
locations, facilitating the transfer
of this data to the state database.
Alternatively, states can request
submittal of an electronic data
summary which contains key per-
formance data formatted for direct
transfer to the state database.
Conclusions
In the majority of pilot states, im-
plementation of an RBDM pro-
gram resulted in an immediate
increase in site closures and a sta-
bilization or decrease in case
backlog. The reduction in case-
backlog represents a decreased
administrative burden for the cor-
rective action program. Average
age at closure generally increased
which, combined with the in-
crease in case closures, indicates
that many older sites are being
closed using RBDM. Evaluation
of site risk classifications in the
backlog population indicates that
the RBDM programs are effec-
tively targeting low-risk sites for
closure while retaining higher-risk
for further action. Additional
study is needed to determine the
impact of RBDM on the remedia-
tion and closure of these higher-
risk sites.
Next Steps
As demand for government ac-
countability increases, more states
will need to utilize performance
measures to document program
performance and identify oppor-
tunities for increased efficiency.
In addition, as a result of the Gov-
ernment Performance and Results
Act of 1993, which requires formal
cost/benefit evaluations of many
federal government programs,
agencies are under increasing
pressure to effectively track pro-
gram performance. Many state
programs are facing similar pres-
sures due to state legislative man-
dates. As state RBDM programs
mature and additional perform-
ance data are collected, future
bulletins may be issued to track
performance assessment efforts
and address specific issues that
may arise. Future bulletins will
be available at:
www.epa.gov / OUST / rbdm
Additional Information
For more information on RBDM
programs and their implementa-
tion, see the following sources:
Websites
OUST Risk-Based Decision-
Making: www.epa.gov/OUST/rbdm
ASTM Standards: www.astm.org
RBCA State Policy Issues Database:
www.gsi-net.com/RBCAPOL
Publications
1. American Society for Testing and
Materials, 1995, "Standard Guide
for Risk-Based Corrective Action
Applied at Petroleum. Release
Sites," ASTME-1739-95, Philadel-
phia, PA.
2. American Society for Testing and
Materials, 1998, "Standard Provi-
sional Guide for Risk-Based Cor-
rective Action," ASTM PS 104-98,
Philadelphia, PA.
Materials, 1999, "Risk-Based Deci-
sion-Making Performance Assess-
ment Study Bulletin #1: Study
Background, Potential Performance
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4. Groundwater Services, Inc., 1995,
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agement, Personnel Communica-
tion.
/ »« u- T-.-O,-. inn^ in if
^S^Dfa 1996 Impact of
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7. USEPA Office of Solid Waste and
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