THE METHOD DETECTION LIMIT AND PRACTICAL QUANTITATION LEVEL: THEIR DERIVATIONS AND REGULATORY IMPLICATIONS

摘要

This paper focuses on the method detection limit (MDL) and practical quantitation level (PQL)used in the sampling and analysis plans for the waste characterization and remediation programsat many federal facilities. The paper discusses the derivation and use of the MDL and PQL bythe Environmental Protection Agency (EPA) and others, concerns raised regarding how EPAderives and uses the MDL and PQL and the regulatory implications, and derivation and use of theMDL and PQL at Waste Isolation Pilot Plant (WIPP) and the associated technical difficulties.EPA’s derivations of the MDL and PQL and the statutory requirements in the Clean Water Actimpacting these derivations are briefly presented. The present-day use of the MDL and PQL inthe Resource Conservation and Recovery Act (RCRA) program and the “codification” of theseanalytical measurements in the SW-846 for RCRA and Part 136 of the Clean Water Act are alsodiscussed. The derivation of the MDL and PQL by others and their guidelines for using them inregulatory programs are compared and contrasted with those of EPA. Also discussed are theconcerns raised by statisticians regarding how EPA derives and uses the MDL and PQL and theassociated regulatory implications.Finally, how WIPP uses the MDL and PQL in its waste characterization program, the technicaldifficulties encountered, and their implications for waste characterization and remediationprograms are discussedSeveral terms in this paper are used analogously and they are listed here to aid the reader:practical quantitation level (PQL), estimated quantitation limit (EQL), program requiredquantitation limits (PRQLs) and the limit of quantitation (LOQ).