Procedures for Detection and Quantitation

Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act (CWA) Programs

Summary of Technical Work Group Conference Call #2
July 13, 2005
1:00 – 2:30 p.m. EDT

The next Technical Work Group call is scheduled for Monday, July 25, from 5:00 – 7:00 PMEDT.

Action Items

Dick Reding will

• Call John Phillips to discuss formation of the subgroup on definitions of detection.
• Post final Technical Work Group summaries on the EPA Det Quant FACA website (http://epa.gov/waterscience/methods/det/) .

Triangle will

• Contact David Rocke and ask if he can participate in the subgroup on definitions of detection on behalf of the environmental community.

John Phillips, a representative for industry, will lead a subgroup formed to work on definitions of detection in preparation for discussion at the July 25 Technical Work Group meeting.  Other subgroup members include:

• Steve Bonde, Environmental Laboratories
• Ken Osborn, Publicly Owned Treatment Works
• Cliff Kirchmer, States
• Brad Venner, EPA
• David Rocke, Environmental Community (if available)

Welcome and Introductions

Vicki King, facilitator, welcomed participants to the call at 1:00 p.m. (EDT), conducted a roll call of Technical Work Group members, and briefly reviewed protocols for the teleconference established on the June 24 teleconference call. (The protocols are listed in the June 24 meeting summary.) She noted that several observers were on the call, and that they would have an opportunity to comment at the end of the call.

Future Dates and Times for Technical Work Group Calls

Ms. King raised the issue of the length of future Technical Work Group meetings. The group agreed to two-hour conference calls. In response to a suggestion that dates and times be set for future meetings, the group agreed to meetings on alternate Wednesdays, from 1:00 to 3:00 PM EDT. However, because of a conference scheduled in Washington, DC for Monday, July 25, which a number of Technical Work Group members will attend, the members agreed to hold their next meeting on July 25, from 5:00 PM to 7:00 PM EDT.

The schedule and times of future Technical Work Group meetings from August through October is as follows – all times are EDT:

• Wednesday, August 10 from 1:00 – 3:00 p.m.
• Wednesday, August 24 from 1:00 – 3:00 p.m.
• Wednesday, September 7 from 1:00 – 3:00 p.m.
• Wednesday, September 21 from 1:00 – 3:00 p.m.
• Wednesday, October 5 from 1:00 – 3:00 p.m.
• Wednesday, October 19 from 1:00 – 3:00 p.m.

Approval of the June 24, 2005 Technical Work Group Meeting Summary

Ms. King asked for comments on the draft summary of the June 24 Technical Work Group meeting which Richard Reding had distributed by email on July 1. The Technical Work Group approved the summary as drafted.

Protocols for Document Management

Ms. King raised the issue of document management and suggested that footers be used to add the following identifying information to documents before they are sent to Richard Reding for distribution:

• File name
• Date
• Source (publication, individual, or group of individuals who developed the document)

She also asked that all documents be reproducible in black and white and encouraged members to minimize the use of color.

She indicated that in the future, agendas for a meeting and documents related to agenda items would be sent to the Technical Work Group in a single email. She suggested that the subject lines of emails be used to distinguish meeting materials from other background materials and documents that Technical Work Group members want to share with one another.

A member urged that materials be sent to Technical Work Group members well in advance of each meeting to allow sufficient time for review and preparation.

Status Report on Detection and Quantitation Procedures

Richard Reding identified the procedures he had sent to Technical Work Group members to date. He clarified that the Interlaboratory Detection Estimate (IDE) and Interlaboratory Quantitation Estimate (IQE) are proprietary and are available for purchase from the American Society for Testing and Materials (ASTM). Mr. Reding also said the Method Detection Limit (MDL) is codified at 40 CFR Part 136, Appendix B, and is available via the Internet.

Discussion of Definitions of Detection

Ms. King then turned to the substance of the meeting. She noted that the Advisory Committee had asked the Technical Work Group to provide definitions of the following terms, along with recommended definitions for use in their process:

• Detection
• Quantitation
• False Positive
• False Negative
• Uncertainty
• L c
• L d
• L q

The purpose of today’s meeting, she said, was to begin discussion of the first of those terms. She called on John Phillips to describe the process that had led to development of the document – “Detection and Quantitation: Definitions and Procedures,” dated 7/12/05 – that had been sent to the Technical Work Group with the agenda for this meeting. He said that he had developed a draft set of definitions, distributed them to members of the Technical Work Group, and received comments from six members; their comments were incorporated in the 7/01/05 draft that he sent to Richard Reding to be distributed to the Group. Mr. Reding distributed it on July 1.

At the request of the facilitators, Mr. Phillips said he had reorganized the terms, to cluster definitions of detection together, definitions of quantitation together, etc. The reorganized document was dated 7/12/05. It was used as the basis of the discussion of definitions of detection.

The group reviewed and discussed the following six definitions of detection that were included in the document:

• ACS Limit of Detection (LOD)
• EPA Instrument Detection Limit (IDL)
• EPA Method Detection Limit (MDL)
• EPA Reliable Detection Limit (RDL)
• IUPAC Critical Value (L C)
• IUPAC Detection Limit (L D) or Minimum Detectable Value

During the course of the discussion, the members agreed that the definitions should be stated exactly as they were in the source documents. The group agreed that the source of the definition should be included with each definition. The group agreed that additional descriptive or operational narrative could be added but, if so, it should be presented in separate paragraphs, below the definition.

Cliff Kirchmer suggested adding two definitions to the list which A.L. Wilson (in the United Kingdom) had developed in the 1960s specifically for water:

• Criterion of detection
• Limit of detection

He said he thought that the wording of those definitions would be more accessible to the non-scientist.

Subgroup to Work on Definition of Detection

Because additional discussion of the definitions of detection was needed, Ms. King asked if a representative subgroup could be formed to continue to work on the definitions of detection in advance of the July 25 meeting. John Phillips agreed to take the lead in forming such a subgroup. (Please see the composition of the group under action items.)

Public Comment

Ms. King then asked observers if they wanted to offer comments.

Tom Georgian of the US Army Corps of Engineers suggested additions to the matrix of procedures and desirable characteristics that had been developed at the June 22 Advisory Committee meeting, entitled Comparison Matrix of Detection and Quantitation Procedures (Version 1: June 29, 2005). He suggested adding a field in the “desirable characteristics” column that would identify the underlying mathematical assumptions in each model (many versus few). He also suggested distinguishing between Type 1 “tolerance” and actual Type 1 errors.

Wrap-up and Closing

Ms. King indicated that continued discussion of definitions of detection would be the primary agenda item for July 25. She encouraged Technical Work Group members to send any additional “desirable characteristics” to Richard Reding to be added to the comparison matrix. Technical Work Group additions, she noted, would be shown in italics to distinguish them from those identified by the Advisory Committee.

Ms. King briefly noted the action items from the call, thanked Technical Work Group members for their participation, and closed the meeting at 2:30 p.m. (EDT).

Attendance

Technical Work Group Members

• States: Timothy Fitzpatrick and Cliff Kirchmer
• Environmental Laboratories: Steve Bonde and Richard Burrows
• Environmental Community:
• POTWs: Ken Osborn 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 - Vicki Kingand Derek Van Marter

Guests

• Joanne Dea (US EPA Conflict Prevention and Resolution Center)
• Tom Georgian (US Army Corps of Engineers)
• Marion Kelly (US EPA Engineering and Analysis Division)
• Patty Lee (Hampton Roads Sanitation District)
• Ken Miller (Consultant)
• Steve Wendelken (US EPA Office of Ground Water and Drinking Water)
• Bob Wyeth (ELAB Chair)