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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 #38
September 13, 2006
1:00 – 3:00 p.m. EST

The call-in number for all calls is 866 299-3188 and the participant code is 202 566 1045#. The schedule of future Technical Work Group conference calls is:

Action Items

Richard Reding will complete a synopsis of the rationale for how the committee arrived at the current working definitions.

The Intermittent Blank Contamination Subgroup will complete a draft discussion paper and circulate to the Technical Work Group for discussion at its next meeting.

Nicole Shao, EPA ORD, will coordinate another conference call with Larry LaFleur, Steve Wendelken, and Larry Wymer of ORD to further develop the document on data calculations/analyses and why a side-by-side comparison of the numerical detection and quantitation limits derived by the procedures may not be appropriate.

Various individuals were assigned the task of revising the Procedures 101 template and forwarding to the Technical Work Group

Triangle will:

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Welcome and Introductions

Bob Wheeler, facilitator, welcomed participants to the call at 1:00 p.m., conducted a roll call of Technical Work Group (TWG) members and observers, and briefly reviewed the agenda for the meeting. He noted that the focus of this meeting will be on the Procedures 101 presentations, and next steps forward to complete those presentations.

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Meeting Summary Approval

Mr. Wheeler asked for comments to the draft August 30 meeting summary. Larry LaFleur suggested a revision in the action items section clarifying why a side-by-side comparison of the numerical detection and quantitation limits derived by the procedures may not be appropriate. The change was accepted. There were no other comments, and the summary was approved as revised.

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Status Updates: FACDQ Extension and Pilot Study

With regard to the pilot study, Richard Reding said the spiking vendor had been selected, and that the contractor was preparing samples. The sample preparation is about two weeks behind the established schedule, but because cushion was built into the schedule, the overall pilot study is on track.

As for the committee re-charter process, Mr. Reding said EPA is preparing the paperwork. He explained that a re-charter process is effectively the same as starting a new committee; they require the same steps, and more steps had been added to the process since EPA originally chartered the committee. He told members of the committee whom are also Technical Work Group members to expect a note from Michael Shapiro outlining the expectations for a charter extension. In summary, Mr. Shapiro said at the July committee meeting that an extension of the committee will largely depend on the progress made on uses, MQOs and other policy issues at its December meeting.

Ken Miller briefly added that with regard to the Michigan Manufacturers' Association (MMA) data, he is working on modeling some of the MQOs, with the exception of false positive rates. He said he likely would not have anything for the group to consider by the next meeting, but that he would have something by October, as laid out in the schedule.

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Technical Work Group Schedule

On that note, Mr. Wheeler reviewed the group's schedule. He asked for some more direction on developing guidance for not meeting qualitative criteria. He said this was an added assignment after the July committee meeting and asked for a volunteer to frame the discussion for the September 27 TWG meeting. There were few responses with many members acknowledging the current amount of work. John Philips said that if he gets the opportunity, he will try to prepare a one-page discussion paper on the topic. If that does not occur, the group agreed to delay discussion of this topic indefinitely.

Richard Reding said that EPA is still working to compile a succinct summary of the rationale for how the committee developed and chose the current working definitions. He said he hopes to have that complete by the next TWG meeting.

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Calculations/Data Analyses Discussions

Mr. Wheeler reminded the group that Larry Wymer, EPA Office of Research and Development, recently expressed concerns of comparing limits across different procedures. That led to an effort to capture rationale for why it may not be appropriate to directly compare limits. Mr. Wheeler said that Larry LaFleur participated in discussions with ORD and others, and that there is a document that exists on the topic. However, the preferred approach is to incorporate the issues into the Procedures 101 presentations to take place in the evening after the first day of the December committee meeting.

Larry LaFleur added that the small group did discuss how the current document would interface with the Procedures 101 presentation, as well as the existing "Features of the Pilot Study" document that Triangle is currently revising. Mr. LaFleur suggested it might be appropriate to have a text version of the issue that is included in the final report of the pilot study to aide readers in reviewing the results and making comparisons across procedures.

Tim Fitzpatrick asked if inter-laboratory design issues would also be incorporated. He suggested the group might consider how to address appropriate uses for the different procedures, because the committee may end up choosing different procedures for different applications.

Mr. LaFleur said the group would get together again to complete its previous discussion, and to address Mr. Fitzpatrick's suggestion. He added that sequencing this topic in the evening presentation at the next committee meeting is important, and that it should be a stand-alone presentation because the issue does not relate specifically to any one procedure.

Mr. Wheeler confirmed that Nicole Shao, EPA ORD, will convene a call of the small group to complete the discussion.

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Intermittent Blank Contamination

John Phillips briefly reviewed progress the subgroup discussing this topic has made. He said they are working on a discussion paper that addressed the following five topics:

  1. Evaluating method blanks
  2. False negative quality control standards (FNQS)
  3. Batch data qualifications
  4. Inclusion of method blanks in detection limit calculations
  5. Process for finding and correcting intermittent blank contamination

Larry LaFleur commented that it sounded as though most of the discussion focused on troubleshooting and characterizing the issue rather than how it is addressed in calculations. The comment sparked a discussion that resulted in an assignment to the subgroup to expand the discussion to include the following three topics before circulating to the TWG for discussion at its next meeting:

  1. Rejection of method blanks;
  2. Initial determination of a limit; and
  3. Censored methods.

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Report on Policy Work Group Discussions

Mr. Wheeler said that the Policy Work Group discussions that potentially involve the TWG are primarily focused with ongoing verification and matrix effects. He reminded the group that Larry LaFleur, who sits on both groups, agreed to keep the TWG apprised of the discussions. He also said that Mr. LaFleur prepared a one-page discussion paper on matrix effects that the Policy Work Group discussed at its last meeting.

Mr. LaFleur briefly walked through the one-page discussion paper for the group's information. He said that he was sharing this information now, because it is very likely the Policy Work Group may ask the TWG for some information on the recommendations in the discussion paper before they make a recommendation for the committee to consider. Mr. Wheeler said Triangle could distribute the discussion paper to the TWG.

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Procedures 101 Presentation

Mr. Wheeler thanked everyone for their work to-date on the presentations. He summarized two issues that have come up since the last meeting: (1) there were questions as to which procedure to use in the case where a procedure had been updated (e.g. Consensus Group and ACIL); and (2) he asked the group to step back for a moment and consider whether this was still the appropriate format to convey to the committee the information currently in the presentations.

Bob Avery suggested that since each presentation addresses the 15 characteristics the committee needs in a procedure, it may be appropriate to find a way to summarize those across all procedures and include that information in each presentation. Many members of the group agreed and thought it would also be helpful to have that in hard copy after the presentations were complete. Mr. Wheeler said Triangle would summarize all 15 characteristics across the 6 procedures in one spreadsheet.

Steve Wendelken asked the group whether it was appropriate to include an "application" slide that explains how the procedure is generally applied in the real world. The group agreed that would be helpful. Mr. Wheeler said Triangle would update the presentation template and circulate that, as well as the revised "What we need a procedure to do" document from the July committee meeting. Mr. Wheeler asked the representatives for each procedure to revise the presentations based on the discussion today, and said that Triangle would send out clear directions on how that should be done in the same email with the revised template and revised characteristics document.

The group discussed two presentations, but being short on time to complete the remaining presentations, decided to pick up the others at the next TWG conference call.

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Public Comment

There were no public comments.

Wrap-up and Closing

Mr. Wheeler summarized the items coming forward for the September 27 meeting:

  1. Status of FACDQ extension
  2. Update on Pilot Study
  3. Procedures 101 presentations
  4. Modified "features" document
  5. Intermittent method blank contamination
  6. Ongoing verification/matrix effects
  7. Definitions rationale

Mr. Wheeler thanked everyone for their time and adjourned the meeting at 3:00 PM, ET./p>

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Attendance

Technical Work Group Members

Triangle Associates: Robert Wheeler and Derek Van Marter

Observers

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