The Environmental Protection Agency (EPA) is finalizing changes to its test procedures required to be used by industries and municipalities when analyzing the chemical, physical, and biological properties of wastewater and other environmental samples for reporting under EPA's National Pollutant Discharge Elimination System (NPDES) permit program. The Clean Water Act (CWA) requires EPA to promulgate these test procedures (analytical methods) for analysis of pollutants. EPA anticipates that these changes will provide increased flexibility for the regulated community in meeting monitoring requirements while improving data quality. In addition, this update to the CWA methods is incorporating technological advances in analytical technology.