The Core Team Process: Making Risk-Informed
Decisions for On-site Monitoring at the SRS
Mary A. Flora
Director, Environmental Compliance & Area Completion Projects
Savannah River Nuclear Solutions, LLC
January 10, 2014
SRS Core Team
The SRS Core Team focuses on making sound,
consensus-based decisions for all aspects of the
SRS remediation program, from initial
characterization efforts through remedial
selection & implementation to post-closure
monitoring and maintenance.
2
Background
• The Savannah River Site
cleanup program began in 1980s
under a RCRA Permit
• SRS was included on the
National Priorities List in 1989
• Cleanup is conducted to meet
both RCRA and CERCLA
requirements and includes:
o
o
o
Soils, groundwater & surface water
remediation
Closure of high level waste tanks
D&D of inactive facilities
• EPA-4 and SCDHEC oversee
cleanup activities
3
SRS Core Team Background
• Established 1999 to improve regulatory & cleanup decisionmaking process
o
DOE, EPA-4, and SCDHEC
• Operates using the 4 Principles of Environmental Restoration:
o
o
o
o
#1: Building an effective Core Team is essential
#2: Clear, concise & accurate problem definition are critical
#3: Early identification of likely response actions is possible, prudent, & necessary
#4: Uncertainties are inherent and will always need to be managed
• Benefits:
o
o
o
Traceable history of in-process decision-making increases confidence
Increased understanding of link between decisions and technical activities
Clear understanding of the known and unknown results in increased confidence that
issues will be identified and managed in time
• Communicate, Agree, Document!
4
SRS Soil & Groundwater Program in 2014
• 400 of 515 contamination units
completed
 68 units require post-closure care
maintenance & monitoring
 24 groundwater plumes in 14 SRS
industrial areas (e.g., A, F, H, M, etc.)
 39 remediation systems
 ~ 2500 monitoring wells with 4100
sampling events
• Mature SRS groundwater
monitoring program
5
Soil & Groundwater Monitoring Optimization
• Initial focus on groundwater
optimization
o
o
o
o
M Area Point of
Compliance Wells
Years of groundwater data
Multiple well installation campaigns
Analytes changes (types and levels)
Required by Permit or Records of Decision
• Initiated optimization efforts
through Core Team
o
ER Principle #4: Uncertainties are inherent
and will always need to be managed
• Core Team recognition that
monitoring needs evolve as work
progresses/for various work stages
• Communicate, Agree, Document!
6
Objectives
• Optimize (right-size) groundwater monitoring
• Evaluate groundwater units individually to ensure discrete
progress and sound, defensible decisions
• Maintain regulatory compliant, environmentally protective, and
technically robust monitoring system
• Benefits:
o
o
Obtain needed data vs redundant, superfluous, poor quality or insufficient data
Reduce demands on samplers, analytical labs, data management & reporting
personnel AND Regulators to reduce overall program costs
7
Optimization Decision Logic
• Core Team agreed to evaluate:
1. Current Monitoring vs. Regulatory
Requirements
2. Spatial Optimization
3. Temporal Assessment
4. Analyte Assessment
5. Reporting Assessment (frequency)
• Technically-based evaluations
• Document decisions through
regulatory documents, including
Permits, RODs, and reports &
plans
8
#1. Compare Current Monitoring to Requirements
• Evaluated
monitoring &
reporting
requirements
specified in RCRA
Permit, RODs, and
RCRA Burden
Reduction Initiative
• Found most units consistent with
requirements
• Eliminated analytes for some units
• Changed submittal of regulatory
reports from semi-annually to
annually for 2 RCRA units
9
#2. Example of Spatial Optimization
• SRS technically evaluated
existing monitoring well network
for individual units (e.g., R-Area)
to determine if well network
provided information required to
meet regulatory requirements,
ensure appropriate information is
being gathered and wells are
located optimally.
• Presented evaluation results to
Regulators & discussed
• Modified regulatory documents,
as needed, and implemented
changes
10
#2. Spatial Optimization
Spatial Optimization Evaluation
2012 Results
For each aquifer unit, consider the following (or
other) questions:
SRS identified spatial optimization as follows:
• Are source/intermediate well(s) providing
unique data regarding the seepage basin
source; located at historic maximum
concentration locations?
• Are plume boundary wells demonstrating that
the plume is not expanding, and is consistent
with model predictions?
• Are auxiliary wells providing trending
information on key contaminants, or are they
spatially redundant?
• Is plume vertically bounded? Are wells focused
on high concentration zones and predicted
zones of breakthrough?
•
9 of 18 units assessed have wells
recommended for discontinued sampling due
to spatial redundancy

4 of 18 units assessed have wells
recommended for addition due to spatial data
gaps
SRS proposed and gained regulator concurrence to
the following:

Discontinue sampling of 72 wells

Incorporate data from 9 existing wells into the
monitoring network

Install 7 new wells to add to the monitoring
network
11
#3. Example of Temporal Optimization of Monitoring Wells
Evaluate for stable or decreasing trends with limited variability over time?
12
#3. Temporal Assessment
Temporal Assessment Evaluation
2012 Results
For each subset of monitoring wells, consider the
SRS identified temporal optimization, as
follows:
following (or other) questions:
• Do source well(s) provide data at a frequency adequate
to detect a release?
• Do plume boundary wells provide data at a frequency
adequate to demonstrate the plume is not expanding,
crossing LUC boundary, or discharging to surface water,
and is consistent with model predictions?
• Do intermediate plume wells provide trending
information on key contaminants considering rate of
change expected based on transport velocities?
• Are effects of active remediation monitored at
frequency to detect significant changes?
• Is monitoring frequency consistent with expected
remedy timeframe (e.g. MNA to take 50+ years,
biennial sampling of intermediate plume wells
adequate)?
• 15 of 18 units have wells recommended for
reduced frequency of sampling
• 1 of 18 units assessed has wells
recommended for increased frequency of
sampling & monitoring due to temporal data
gaps
SRS proposed and gained regulator
concurrence to the following:
• Reduce sampling frequency for a total of 346
wells.
• Increase sampling frequency for a total of 42
wells (primarily water levels for wells located
around an operating air stripper that is being
evaluated for shutdown)
13
#4. Analyte Assessment
Analyte Assessment
For each analyte, consider the following (or other) questions:
• What is the regulatory driver (e.g. contaminant of concern
[> MCL], corrective action constituent, monitoring
constituent [> background concentrations], geochemical
indicator [pH, ethene,etc.]?
• Do reporting requirements (i.e., 5-Year ROD Review)
require continued analysis?
• Can a class of contaminants (e.g. metals) be eliminated?
Can other contaminants be used as a bounding case
considering the spatial extent and concentration level?
• What is the frequency of detection above the limit (or at
all) in a given well or network?
• Does trend analysis across plume support future
predictions that analyte will no longer provide useful data
2012 Results
SRS identified temporal optimization, as
follows:
• 3 of 18 units have analytes
recommended to be discontinued
• 3 of 18 units have analytes
recommended to be added to sampling
& monitoring regimen
SRS proposed and gained regulator
concurrence to the following:
• Reduce analytes assessment for a total
of 363 wells.
• Added analytes to be assessed at a total
of 75 wells (Note: of these 75 wells, 65
wells were added to assess 1,4-dioxane)
to support remedy or decision-making?
14
#5. Reporting Assessment
Reporting Assessment
For each report, consider the following (or other) questions:
• Can a subset of wells be utilized for time trends?
• Can statistical analysis be eliminated or postponed?
• Can a subset of plume maps be representative?
• Can units be combined?
• Can map scale be modified for ease of use?
2012 Results
SRS identified temporal
optimization, as follows:
• 6 of 18 units have requests to
reduce reporting frequency
recommended to be discontinued
• Major content modification
recommended for 1 of 18 units due
to completion of remediation and
shutdown of remediation system
SRS proposed and gained regulator
concurrence to these
recommendations for reporting
improvements
15
Optimization Results and Summary
• Early & frequent Core Team deliberations ensured process
was successful and all parties agreed
– Expanded to included remediation systems
• Technical evaluations were basis for all evaluations,
recommendations & decisions
• Decisions were documented
• Core Team optimization process accepted as standard process
and continuing
QUESTIONS?
16