January 30, 2013

DTSC Chatsworth Office Marina Perez

Raymond Leclerc Mark Malinowski

Laura Rainey

Ground Rules

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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.

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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2011 2017 2012 2013 2014 2015 2016

Building Demolition

Chemical Data Gap Investigation

Treatability Studies

EPA Rad Sampling/ DTSC Chemical Co-Located Sampling

Soils Remedial Action Implementation Plan

Approved Plan

Soils Cleanup Implementation

Confirmation Sampling

Final Rad Data Report

Final Chem Data Report

Anticipated SSFL Project Timeline January 30, 2013

Feb 2013

CEQA Scoping CEQA Assessment

CEQA Document

EPA Rad Background

Study

DTSC Chemical Background Study

Final Rad Background

Report

Final Chem Background

Report

Provisional Rad Lookup

Tables

Chem Lookup Tables

Final Rad Lookup

Tables Rad Lab Selection

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

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‘True Concentration’

Range of Measurements at True Concentration

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easu

rem

ents

Concentration

Decision Error For decisions, we specify up front how much error is

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

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‘True Concentration’

Range of Measurements at True Concentration

# o

f M

easu

rem

ents

Concentration

Draft Provisional Rad Look-Up Table Example - Cesium 137

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Provisional LUT Value = BTV+ 1.645*Method Uncertainty

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

# o

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easu

rem

ents

Concentration

Radiological Look-Up Table Process

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BTVs or MDCs AOC requires radiological

cleanup levels to include local background levels (BTVs) or

minimum detectable concentrations (MDCs)

LUT Value = BTV (or MDC) + Decision Error Factor (1.645)*Method Uncertainty

Using independent technical judgment

based on science, USEPA recommends

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

marina.perez@dtsc.ca.gov

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