This book presents a 20-year historical overview and comprehensive study results of the aquatic environment affected by the 1986 Chernobyl nuclear accident. The book analyzes water remediation actions, using current science and mathematical modeling, and discusses why some were successful, but many others failed. This book will interest engineers, scientists, decision-makers, and everyone involved in radiation protection and radioecology, environmental protection and risk assessment, water remediation and mitigation, and radioactive waste disposal.