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Procedures for Detection and Quantitation
Note: EPA no longer updates this information, but it may be useful as a reference or resource. Proposed rule withdrawal fact sheet.
Notice of Document Availability and Proposed Rule
Fact Sheet, February 2003
EPA seeks comment on an assessment of procedures for determining sensitivity (i.e., detection and quantitation) of test methods. EPA also seeks comment on a proposed rule revising the Definition and Procedure for the Determination of the Method Detection Limit (40 CFR Part 136, Appendix B). The proposal responds to stakeholder and peer review comments and incorporates clarifications and improvements based on the assessment.
Background
The U.S. Environmental Protection Agency (EPA) uses the method detection limit (MDL) and minimum level of quantitation (ML) to determine analytical test sensitivity under the Clean Water Act (CWA). The MDL is used to determine the lowest concentration at which a substance is detected or is "present" in a sample. The ML is used to describe the lowest concentration of a substance that can be reliably measured in a sample. The MDL procedure was published in the Code of Federal Regulations (CFR) at 40 CFR Part 136, Appendix B in 1984.
EPA's Assessment of Detection and Quantitation Procedures
EPA assessed current procedures for determining the sensitivity of test methods and their application to CWA Programs. The assessment was required by a settlement agreement with the Alliance of Automobile Manufacturers, et al. It is entitled, "Technical Support Document for the Assessment of Detection and Quantitation Concepts" (EPA 821-R-03-005, February, 2003). This document discusses statistical, chemical, and regulatory issues related to detection and quantitation and different approaches to detection and quantitation. The Agency now seeks public review and comment on this assessment.
Proposed Revisions to 40 CFR Part 136, Appendix B
Based on our recent assessment and on stakeholder comments we have received over the years, EPA is proposing revisions to the MDL procedure codified at 40 CFR Part 136, Appendix B. In addition to specific technical and editorial changes to the MDL procedure, EPA is revising the definition of the MDL, adding a definition and procedure for determining the ML, and clarifying the acceptance of alternative detection and quantitation procedures. EPA seeks public review and comment on this proposal.
Additional Information and Copies
You can get more information by contacting the EPA Office of Water, Engineering and Analysis Division (4303T), 1200 Pennsylvania Avenue, Washington, D.C. 20460.
You can view and download the complete text of the Federal Register notices by visiting the detection and quantitation Web site. You can also get copies of the notice and other documents by calling the Water Resource Center at 202-566-1729.