January 30, 2013
DTSC Chatsworth Office
Marina Perez
Raymond Leclerc
Mark Malinowski
Laura Rainey
Ground Rules
Please:
• Silence all mobile phones, PDAs, tablets and electronics
• Limit cross conversation during the meeting
• Treat other people with the same level of respect you expect
from others
• Hold all questions until the designated question and answer
period(s)
Photography, sound and video recording may occur during this meeting. If
you do not wish to be filmed or photographed please inform the
photographer/videographer directly.
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Agenda
 Introduction/Ground Rules
 Meeting Goals
 Radiological Look-Up Table Process
 Administrative Orders on Consent
 EPA Recommendations Recap
 Example Radionuclides
 Timing and Use of Provisional Values
 Next Steps
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Meeting Goals
 DTSC will describe the development of the Look-Up Table
process and the community’s role in that process
 Review how the Look-Up Table is described in the AOC
 Explain how the Look-Up Table process complies with the
AOC
 Considerations while establishing the Look-Up Table values
 Review the process going forward, highlighting opportunities
for the community to stay informed
 DTSC will describe how the Look Up Table process will be
applied for:
 Remediation planning
 Confirmation
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Anticipated SSFL Project Timeline
EPA Rad Sampling/
DTSC Chemical Co-Located Sampling
January 30, 2013
Final Rad
Data Report
Building Demolition
Final Chem
Data Report
Chemical Data Gap
Investigation
Treatability Studies
Approved
Plan
Soils Remedial Action
Implementation Plan
Soils Cleanup Implementation
Confirmation Sampling
CEQA
Document
CEQA Scoping
CEQA Assessment
Final Rad
Background
Report
EPA Rad
Background
Study
Rad Lab
Selection
Final Chem
Background
Report
DTSC Chemical
Background Study
2011
Final
Rad Lookup
Tables
Provisional
Rad Lookup
Tables
2012
Chem
Lookup
Tables
2013
Feb 2013
2014
2015
2016
2017
Administrative Order on Consent
 DTSC is responsible for the enforcement and
implementation of the AOCs – including establishing
Look-Up Table values
 Although the AOCs state what will be included in the
Look-Up Table, it does not provide specific values, nor
detail the process to define those values
 DTSC is responsible for establishing the Look-Up Table
with technical input from EPA
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Administrative Order on Consent
 What does the AOC tell us about what the Look-Up
Table values should be?
“Upon completion of the EPA led radiological
local background study, a “look-up” table of the
radiological cleanup levels will be prepared, which
will include both local background concentrations
as well as minimum detection limits for specific
contaminants whose minimum detection limits
exceed local background concentrations.” (AIP,
p.2)
[underline added]
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EPA’s Look-Up Table
Recommendations
From the EPA’s Look-Up Table Technical Memorandum
(p.5):
“While DTSC may select LUT values that are equal to the cleanup
levels [BTV or MDC], it is USEPA’s understanding that the
extraordinarily high decision error rate for laboratory results at or
near those cleanup levels is believed unacceptable. In exercising
independent technical judgment, as identified in Section 5.2 of the
AOC, USEPA recommends an adjustment to the BTVs and
minimum detectable concentrations (MDC) to include appropriate
consideration for Um [method uncertainty] to ensure an acceptably
low decision error rate of 5 percent.”
[added definitions inserted and underline added]
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EPA’s Look-Up Table
Recommendations
• Final Radiological Look-Up Table values
should be derived using EPA’s BTVs
(Background Threshold Values) or future lab
MDC (Minimum Detectable Concentrations –
for radionuclides with BTVs below the MDC)
and
• Respective BTV/MDCs should be adjusted to
address Analytical Method Uncertainty (Um)
and Decision Error
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Analytical Method Uncertainty
 Each reported sample result exists within range of
possible measurements of a ‘true’ value
Number of Measurements
‘True Concentration’
Range of
Measurements
at True
Concentration
Concentration
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Decision Error
 For decisions, we specify up front how much error is
# of Measurements
acceptable – 5% error means 95% confidence
 This approach is consistent with DTSC practice, EPA
practice and how cleanups are done across the country
 Allows us to know with a greater level of certainty when
to stop digging
‘True Concentration’
Range of
Measurements
at True
Concentration
Concentration
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Draft Provisional Rad Look-Up
Table Example - Cesium 137
Provisional LUT Value = BTV+ 1.645*Method Uncertainty
# of Measurements
BTV = 0.193 (MDC=0.0198)
Uncertainty = 10%*BTV
= 10%*0.193 = 0.0193
Provisional LUT Value = 0.193 + 1.645*0.0193
Provisional LUT Value = 0.225
Concentration
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Radiological Look-Up Table Process
BTVs or MDCs
AOC requires radiological
cleanup levels to include local
background levels (BTVs) or
minimum detectable
concentrations (MDCs)
Using independent
technical judgment
based on science,
USEPA recommends
LUT Value = BTV (or MDC) + Decision Error Factor (1.645)*Method Uncertainty
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Look-Up Table Process Summary
 EPA recommended adjusting the BTV/MDC to
account for uncertainty and decision error in the
Look-Up Table value
 Accounting for uncertainty and decision error is a
standard regulatory practice in setting cleanup values
 Science defines how to make these adjustments
 Adjustments to the BTV/MDC are relatively small
increases because the starting levels are small
(background)
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So - Where are we now?
 EPA Radionuclide Background Study
 EPA demonstration of laboratory capabilities relative to
Minimum Detectable Concentrations
 Analysis of current laboratory industry capabilities
relative to Minimum Detectable Concentrations
 EPA has recommended a Look-Up Table development
process
 DTSC accepted EPA’s recommendations
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Provisional Look-Up Table Values
 Provisional LUT values will be based on EPA BTVs and
MDC information from the EPA study, and recent lab
responses for the lowest, routinely achievable MDCs
 Provisional LUT values are important since they keep
the project moving
 They allow development draft remedial plans
 They allow CEQA and NEPA to proceed
 Draft remedial plans will allow a radiological lab to be
selected and Final LUT values established prior to
cleanup
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Conclusion
 The AOC requires a cleanup to background
 The Look-Up Table has to be technically defensible so
that DTSC will have a greater level of certainty that the
process identifies contamination above background
 EPA provided enough information to allow
development of Provisional Radiological Look-Up
Table values and keep the project moving
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Next Steps for Look-Up Table
Development
DTSC to complete evaluation and develop Provisional
Radiological Look-Up Table
Complete Provisional Radiological Look-Up Table in
Spring and post to DTSC website
Apply relevant EPA recommendations to develop
Chemical Look-Up Table
Next meeting will be on Chemical Look-Up Table
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Questions
Community Involvement
 Monthly SSFL Progress Report via email
http://www.dtsc.ca.gov/sitecleanup/Santa_Susana_Field_Lab/
 Ongoing Community Meetings/Calendar
 Community Notices aka Fact Sheets, Public Notices,
E-list, etc.
For questions regarding SSFL and Community Involvement
contact
[email protected]
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