This is the fourth volume in the series of books on the Southeast Asian water environment. The most important articles presented at the Sixth and Seventh International Symposiums on Southeast Asian Water Environment have been selected for this book. It covers water environment management, biological and physico-chemical processes in water and wastewater treatment, monitoring approaches, and water related health issues.  This publication is the result of building an academic network among researchers of related fields from different regions to exchange information. This book will be an invaluable source of information for researchers, policy makers, NGOs, NPOs, and those who are concerned with achieving global sustainability within the water environment in developing regions.