Clean Water Act Methods Update Rule for the Analysis of Effluent

EPA proposes changes to pollutant analysis methods that are used by industries and municipalities to analyze the chemical, physical, and biological components of wastewater and other environmental samples that are required by regulations under the Clean Water Act. EPA designed the proposed changes to increase flexibility for the regulated community, improve data quality, and update CWA methods to keep current with technology advances and analytical methods science. EPA updates and revises the CWA analytical methods from time to time, the most recent updates being completed in 2012. The new set of proposed changes described in this notice include revisions to current EPA methods and new and/or revised methods published by voluntary consensus standard bodies, such as ASTM International and the Standard Methods Committee. EPA also proposes to approve certain methods reviewed under the alternate test procedures program and clarify the procedures for EPA approval of nationwide and limited use alternate test procedures. Further, EPA proposes amendments to the procedure for determination of the method detection limit to address laboratory contamination and to better account for intra-laboratory variability.