Procedures for Detection and Quantitation

WORKING DRAFT FOR DISCUSSION

Draft Evaluation Criteria for a Final Package of Detection and Quantitation Recommendations

At the December 8-9 meeting, the members of the FACDQ Advisory Committee will be asked to approve a working draft of evaluation criteria for a final package of detection and quantitation procedures to recommend to EPA. Typically, broad, policy-level criteria are used to evaluate a final package of recommendations.

At the September Advisory Committee meeting you approved by consensus a draft set of evaluation criteria, with the proviso that you would revisit them at a later meeting. Following that meeting, the facilitators consolidated and restructured the draft evaluation criteria you approved. The facilitators' version is presented below.

On December 8-9, the Committee will have an opportunity to review the draft evaluation criteria and determine if they meet the Committee's needs. Please consider the following questions as you review the draft evaluation criteria. Are they clear? Is anything missing? Are there redundancies that can be removed? If revisions are needed, what changes should be made? Are the criteria identified separately for detection, quantitation and implementation at the end of the document appropriate? Should they be incorporated in the list above? Are they needed?

Criteria for the Final Package as a Whole

Is a complete, tested, understandable, consistent, written procedure that addresses both detection and quantitation
- (Please note: This criterion originally included promulgation of the procedure at 40 CFR Part 136 Appendix B. Because rulemaking would be required to establish new procedure/s in regulation, the facilitators suggest that the Committee indicate a desire and expectation that any procedure/s the Committee agrees to by consensus go into rulemaking after the Committee's work ends. This would capture the Committee's intent without including rulemaking among the criteria.)
Provides confidence in detection and quantitation procedures at low enough levels to protect human health and the environment
Provides explicit definitions for a detection limit and a quantitation limit
Determines in an unambiguous and legally-defensible manner compliance with the Clean Water Act
Meets use needs
Provides technically-valid procedure(s)
Defines measurement quality objectives for different uses
Must be flexible enough to address matrices (e.g., sample interference)
Includes method blank correction but with maximum acceptable blank concentration as a percentage of the quantitation limit
Includes a statement of uncertainty level around detection and quantitation limits
Includes a procedure for validation and a procedure for laboratories
Reflects routine laboratory operations
Balances cost and rigor

Detection Procedure(s) - Additional criterion beyond those listed above

Must address both false positives and false negatives

Quantitation Procedure(s) - Additional criteria beyond those listed above

Includes explicit measurement quality objectives, including precision and bias and accounting for interlab variability
Reflects appropriate quality control
Has a calibration check at the quantitation limit with predetermined recovery rates

Implementation of Procedure(s)

Provides guidance document (e.g., SW846-method 5035A)

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