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Procedures for Detection and Quantitation
Technical Workgroup
Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act (CWA) Programs
Summary of Technical Work Group Conference Call #13
November 16, 2005
1:00 – 3:00 p.m. EDT
- Action Items
- Welcome and Introductions
- Draft Meeting Summary
- Discussion of Revisions to Descriptions of Characteristics
- Purposes and Objectives of a Pilot Study
- Report from Multi-lab Subgroup
- Report from Single-lab Subgroup
- Public Comment
- Wrap-up and Closing
- Attendance
- Back to Technical Workgroup home page
**NOTE ADDITIONAL CALL** The next Technical Work Group call is scheduled for Monday, November 21, from 4:00 - 5:30 PM EST.
Action Items
Jim Pletl will revise the approved characteristics based on today's discussion.
Larry LaFleur will finalize the Multi-lab Subgroup progress report.
Richard Burrows will finalize the Single-lab Subgroup progress report.
David Kimbrough and Ken Osborn will send to Triangle RDL definitions for the glossary of terms.
Triangle will:
- Revise the draft purposes and objectives.
- Revise the glossary of terms.
- Distribute materials to Technical Work Group members in advance of the November 21, 2005 conference call.
Welcome and Introductions
Robert Wheeler, facilitator, welcomed participants to the call at 1:05 PM EST. He conducted a roll call of Technical Work Group members and observers, and briefly reviewed the agenda for the meeting. Mr. Wheeler emphasized the purpose of the meeting was to approve products for the December federal advisory committee meeting.
Draft Meeting Summary
Mr. Wheeler asked for comments to the draft November 9, 2005 Technical Work Group meeting summary. There were no comments and the summary was approved, as drafted. David Kimbrough abstained from the motion since he was not present at the November 9 meeting.
Discussion of Revisions to Descriptions of Characteristics
Mr. Wheeler asked Jim Pletl to briefly review the revisions he had made to the draft descriptions of characteristics. Mr. Pletl said he had received several comments for revision to the draft document that he wanted to review with the group. In discussing each of the suggested revisions, the group approved the following amendments for completing the document and distributing to the committee:
- Concentration Estimate Uncertainty - Does the procedure provide estimates of bias and/or precision as a function of concentration? (Y/N)
- Consistent or Chronic Blank Bias Addressed - Does the procedure explicitly adjust or account for situations where method blanks always return a non-zero result/response (e.g. defects in calibration or consistent or chronic contamination of laboratory blanks). Respond with "NC" if the procedure does not adjust or account for situations where method blanks always return a non-zero result/response but could be modified to do so and footnote effort required for this modification. (Y/N/NC) Comment: need to clarify what is being asked and why.
- Intermittent Blank Contamination - Does the procedure explicitly adjust or account for situations where method blanks are intermittently contaminated? Respond with "NC" if the procedure does not explicitly adjust or account for situations where method blanks are intermittently contaminated but could be modified to do so and footnote effort required for this modification. (Y/N/NC). Comment: Is this characteristic applicable to detection /quantitation procedures?
Purposes and Objectives of a Pilot Study
Mr. Wheeler asked members to review the purposes and objectives document developed by the facilitators, based on information and feedback from the subgroups during the last conference call. The group agreed that the document should be revised to more clearly reflect the following purpose and objective of a pilot study.
- Purpose - collect information about various detection and quantitation procedures that will be helpful to the federal advisory committee in its deliberations of detection and quantitation approaches and uses in Clean Water Act programs.
- Objective - design a study that answers the following questions. (The questions identified by the Technical Work Group and captured in the November 9 meeting summary would follow.)
During the course of discussion, the Technical Work Group identified a policy issue needing committee deliberation: whether a procedure should allow for blank correction. There was considerable discussion as to whether analytical methods also should allow for blank correction. Some members acknowledged the work load in retroactively implementing blank correction in analytical methods that do not currently allow it. Others suggested that the focus should be on moving forward with a procedure that best fits the desires of all the interests at the table, regardless of issues with current analytical methods.
Mr. Reding asked if allowing blank correction in the pilot analytical methods was a barrier to moving forward with the pilot of promising detection and quantitation procedures. There was discussion about this, and about whether the definition of Lc should compare the signal to zero or to the mean of the blank signals, which can be nonzero. Members agreed that resolution of the issue of the zero vs. blank choice in the Lc definition was necessary in moving forward with designing a pilot study. Resolution of the other- allowing for blank correction in the analytical method - is important, but does not prohibit moving forward with the pilot study design. The Policy Work Group members are also working the zero vs. blank definition issue. The Technical Work Group members agreed that it may be wise to elevate both issues to the FACDQ committee at the December meeting.
Report from Multi-lab Subgroup
Larry LaFleur reported for the Multi-Lab Subgroup. He reiterated some of the issues reported during the last conference call, saying that the subgroup progress report would likely not change much in content other than removing the listing of objective questions, since those would be included in a separate document. Richard Reding recommended a statement be added to the Potential Use of Existing Data section explaining the need to pre-qualify the data. Mr. Wheeler recommended the policy questions needing committee attention be moved to the front of the progress report so that it is clear where the Technical Work Group wants committee input.
Report from Single-lab Subgroup
Richard Burrows reported for the Single-Lab Subgroup briefly reviewing the progress report distributed via email to Technical Work Group members. He said the subgroup had already identified the major policy question it needs answered, and the question is identified in the beginning of the progress report. He also said the subgroup would add a statement about the need to pre-qualify existing data.
Public Comment
Francois Rodigari, of East Bay Municipal Utility District, briefly addressed the Technical Work Group. He said there are two distinctions with regard to the questions posed by the Single-lab Subgroup as to requiring:
- a detection or quantitation procedure to identify the lowest level that a single lab could detect or quantitate; or
- a detection or quantitation procedure to verify that the lab can detect or quantify at its stated limit.
He said the first represents a snap-shot in time, whereas the second is an on-going demonstration of meeting performance characteristics. The latter more accurately reflects routine performance.
Wrap-up and Closing
The dates and times (all are EST) of future Technical Work Group meetings are as follows:
- Monday, November 21 from 4:00 - 5:30 p.m.
- Finalize products for the federal advisory committee
- Wednesday, November 30 from 1:00 - 3:00 p.m.
- Prepare presentation approach for federal advisory committee meeting and finalize two issue papers
- Wednesday, December 14 from 1:00 - 3:00 p.m.
- Wednesday, January 4, 2006 from 1:00 - 3:00 p.m.
- Wednesday, January 18, 2006 from 1:00 - 3:00 p.m.
Mr. Wheeler briefly noted the action items from the call, and said the agenda for the next call was to finalize products from the Technical Work Group for distribution to the committee. He thanked Technical Work Group members for their time and closed the meeting at 3:05 p.m. EST.
Attendance
Technical Work Group Members
- States: Cliff Kirchmer and Bob Avery
- Environmental Laboratories: Richard Burrows and Steve Bonde
- Environmental Community:
- POTWs: Ken Osborn, David Kimbrough, and Jim Pletl
- Industry: Larry LaFleur and John Phillips
- US EPA: Richard Reding (Office of Water) and Brad Venner (Office of Enforcement and Compliance Assurance)
- Other Federal:
Triangle Associates: Derek Van Marter and Robert Wheeler
Observers
- Ken Miller (Consultant to EPA Office of Water)
- Francois Rodigari (East Bay Municipal Utility District)