With approximately 80 methods revised and 5 new methods added, Standard Methods for the Examination of Water and Wastewater, 23rd edition provides the most up-to-date, comprehensive resource for measuring the biological, chemical, and physical attributes of waters and offers guidance for choosing among available methods for specific elements and compounds. Analysts, researchers, and regulators have relied on this peer-reviewed publication since 1905, and it remains a trusted source of accurate, proven methodology for analyzing natural waters, water supplies, and wastewaters.