Welcome to the companion website for Water Chemistry. The site provides extensive supplemental resources for each chapter and access to software used in examples and needed to solve problems throughout the book. The supplemental resources include textually based web boxes that augment topics not fully covered in the book, spreadsheets of data for some end-of-chapter problems, pdfs of text tables with values of important constants, and complete reference citations for each chapter. Other links at the left include a list of errata that will be updated as the authors or readers report them, photos of natural and engineered aquatic systems that users may download for presentations, and a solutions manual for end-of- chapter problems (accessible only to instructors).