August 15, 2017

Method Detection Limits and Regulatory Levels

Analytical procedures, particularly when dealing with complex wastes, may require significant dilution of a sample. This can often result in method detection limits (MDLs) being higher than regulatory thresholds. For example, you may get a TCLP result from a lab noting that mercury is nondetect; however, the MDL is noted as being 1.0 mg/L, which is higher than the regulatory level of 0.2 mg/L. In these circumstances, it is not possible to determine conclusively whether the waste is hazardous for mercury or not. [RO 11579, 11592, 11627]

So, this is a good reminder for when you are reviewing analytical: always check the MDLs as well as the results. If the MDL is higher than the regulatory level, the result may not be usable for RCRA hazardous waste determination purposes.


©2017-2023 McCoy and Associates, Inc. All rights reserved.

McCoy and Associates has provided in-depth information to assist environmental professionals with complex compliance issues since 1982. Our seminars and publications are widely trusted by environmental professionals for their consistent quality, clarity, and comprehensiveness.



Considerable care has been exercised in preparing this document; however, McCoy and Associates, Inc. makes no representation, warranty, or guarantee in connection with the publication of this information. McCoy and Associates, Inc. expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal law or regulation with which this information may conflict. McCoy and Associates, Inc. does not undertake any duty to ensure the continued accuracy of this information.

This document addresses issues of a general nature related to the federal RCRA regulations. Persons evaluating specific circumstances dealing with the RCRA regulations should review state and local laws and regulations, which may be more stringent than federal requirements. In addition, the assistance of a qualified professional should be enlisted to address any site-specific circumstances.