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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
- Action Items
- Welcome and Introductions
- Meeting Summary Approval
- Developing Work Strategy for the PAT
- Intermittent Method Blank Contamination
- Public Comment
- Wrap-up and Closing
- Attendance
- Back to Technical Workgroup home page
Summary of Technical Work Group Conference Call #46
January 22, 2007
1:00 – 2:30 p.m. ET
The next Technical Work Group call is scheduled for Wednesday, January 31, 2007, from 1:00–2:30 p.m., ET. The call-in number is 866-299-3188; access code is 202 566 1045#.
Action Items
Ken Miller will:
- Send out normality graphs to the TWG
- Send out an e-mail with the final versions of previously sent data
- Send a summary of multi lab responses to Nicole Shao
- Release the individual data point information on a method-by-method basis over the next month.
Ken Osborn will send out his analysis of single lab limits for Lab QC.
John Phillips will send out additional comments on false positive parameter evaluations.
Welcome and Introductions
Bob Wheeler, facilitator, welcomed participants to the call at 1:08 p.m. ET, conducted a roll call of Technical Work Group (TWG) members and observers, and briefly reviewed the agenda for the meeting.
He said that the primary focus of the meeting would be for the TWG to provide input towards the deliberations and analysis of data the Pilot Analysis Team (PAT) would be conducting later in the week in Seattle. Mr. Wheeler also mentioned that the topic of Intermittent Method Blank Contamination would be tabled until the next meeting as Steve Wendelken would not be available today to discuss that agenda item.
Meeting Summary Approval
Mr. Wheeler asked for comments to the draft January 10 meeting summary. There were no comments and the group approved the summary as drafted.
Developing Work Strategy for the PAT
Mr. Wheeler reviewed the reference materials distributed for this meeting and then asked Ken Miller for comments on the series of files he had sent out last week. Mr. Miller discussed the multiple versions and noted that because there were, he would send a final list of the most recent documents. He also mentioned that he planned on sending out a list of compiled comments on the ACL procedure. Mr. Miller said he would also resend the 'Example Graphs of Pilot Study data - RSD MQO' and 'Example Graphs of Pilot Study Data - Mean Recovery MQO' to the TWG since only the PAT received them. Nicole Shao inquired if Mr. Miller had received any responses to multi lab analysis to which Mr. Miller replied that he had received one response, a positive one, to multi lab analysis. She requested a summary of that response once he returned from Seattle.
Mr. Miller said he will be bringing descriptive stats of the pilot study data to Seattle. He said that any questions regarding 'why a limit did not get calculated by a lab' would be hard to answer and that he would have to get back to those questions once he returns from Seattle. Regarding the PAT meeting, if specific questions come up about data points or other inquiries, Dick Reding said that the information would not be readily available in Seattle but that the PAT could call back to their sources and get the answers. Larry LaFleur asked Mr. Miller when all the individual data points would be available for review to which Mr. Miller replied "in the next couple weeks."
Various members of the TWG thanked Mr. Miller for all his hard work analyzing and evaluating the data.
- Ken Osborn reminded the group that there are more procedures being evaluated than in the Pilot Study. He said that he will send out data that his lab compared on the ACIL to the TWG. Bob Wheeler reminded the group that the PAT will also be reviewing the procedures not tested through the pilot study.
- John Phillips advised the group that there is a need to focus on other criteria and not just limits; that decisions based on limits are too confusing and that the PAT should be encouraged to focus on FACDQ direction. Mr. Wheeler reiterated that point by saying the TWG had previously stated it would not focus on specific limits and that limits would be reported but that they should caution against specific comparison.
- Tim Fitzpatrick asked Mr. Miller about instrumentation sensitivity and the possible need of looking further into data since he noticed a big difference between median and mean in false positive rates. Mr. Miller said he suspects those differences are for various reasons beyond instrumentation sensitivity.
- David Kimbrough inquired as to the goal of the PAT to which Mr. Wheeler replied. He said the intent of the meeting is to review the FACDQ assignment, look at results and recommendations of data, to start putting together the pilot study report, to discuss procedures that were and were not a part of the pilot study, to think about all this in terms of the "What do we need a procedure to do" document, to make initial procedural recommendations, and to decide what the TWG needs to do with this information.
- Mr. Kimbrough mentioned that his biggest concern is that the data is dominated by non-normally distributed data and so it can't be used for normally distributed data. He said the PAT should look at results in terms of calculated limits and gut level reactions to numbers. Brad Venner said that developing normative rates seems like one of the biggest challenges.
There was some discussion within the group about the necessity of this evaluation with such few data points and whether or not this analysis would properly stand up to the criteria decided by the FACDQ and written in the document "What Do We Need A Procedure To Do." To ease these qualms and maintain focus it was suggested that Mr. Miller, suing input from this TWG discussion, write up a short paragraph explaining his vision regarding the interpretation of data and what he thinks could be accomplished from this. Mr. Miller mentioned that he could have that narrative ready by the next TWG meeting and that he was also working on completing a list of lab comments for the ACIL procedure. He added that some labs have expressed concern over spike levels for silver so he is not using some of that data and also that the LCMRL calculator is dropping out negative numbers and zeroes so he is manually taking time to recalculate these limits.
Intermittent Method Blank Contamination
Steve Wendelken, the proponent of this topic, was absent from the call and so Mr. Wheeler decide to table the issue until the next meeting.
Public Comment
There were no public comments.
Wrap-up and Closing
Mr. Wheeler reminded everyone that the next call would be on Wednesday, January 31 from 1-3 PM, ET and that the TWG would hear a report out from the PAT.
He thanked everyone for their time, reviewed some minor travel logistics for the PAT, including Seattle weather and dress, and adjourned the meeting at 1:57 PM, ET.
Attendance
Technical Work Group Members
- States: Tim Fitzpatrick and Bob Avery
- Environmental Laboratories: Richard Burrows
- POTWs: Ken Osborn, Jim Pletl, and David Kimbrough
- Environmental Community: Richard Rediske
- Industry: Larry LaFleur and John Phillips
- US EPA: Dick Reding and Brad Venner
- Other Federal:
Triangle Associates: Robert Wheeler and Cole Gainer
Observers
- Zonetta English (Public Utilities committee member and Pilot Design Team member)
- Ken Miller (Consultant to EPA Office of Water)
- Brian Englert (US EPA)
- Nicole Shao (EPA Office of Research and Development)