Guidelines Establishing Test Procedures for the Analysis of Pollutants; Procedures for Detection and Quantitation

EPA uses method detection limit (MDL) and minimum level of quantitation (ML) procedures to establish detection and quantitation capabilities of test procedures (i.e., analytical methods) 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 in a sample that can be measured with a known level of confidence. Today's notice announces the availability of a document entitled Revised Assessment of Detection and Quantitation Approaches. This document presents EPA's revised assessment of MDL, ML and other detection and quantitation procedures for use under the CWA, and EPA's consideration of public comment received on an assessment document published by EPA in 2003.