AWWA JAW26637

This article describes the role of the laboratory in developing and determining compliance with maximum contaminant levels (MCLs) under the Safe Drinking Water Act (SDWA). It begins with a brief overview of the pertinent provisions of the SDWA and discusses laboratory performance variability. The article also details how the US Environmental Protection Agency develops MCLs and highlights how laboratory performance variability can impair a water system's ability to comply with those limits. Some suggestions are offered designed to help water systems cope with analytical variability in the regulatory process and include: analyze at a high-quality laboratory; select with care the method used for compliance purposes, when there is a choice; report data properly; compliance monitoring data should be reported along with error band that is associated with the test method used; and maintain good relations with regulators. Includes 29 references, tables.