Freshwater is a finite resource as essential to agriculture and industry as it is to basic human existence. Water quality monitoring is a fundamental tool in the management of freshwater resources, and this book comprehensively explores the entire monitoring operation. This essential work: highlights the impact of human activity on water resources - both surface and groundwater; provides a general protocol for the design and implementation of a monitoring programme; provides detailed sampling and analytical methods; explains the detection and monitoring of trends in the water environment. This book provides a sound basis for designing and implementing water quality monitoring programmes and studies of the impact of human activities on water bodies. It brings together information on proven methods and thus will be useful for anyone concerned with water quality monitoring a scientific, managerial or engineering background, including field staff. An overview of the principles underlying hydrological, chemical, biological and sediment measurements together with their importance and relevance to water quality monitoring is also included. This important text is the outcome of a collaborative programme of activity between UNEP and WHO, with inputs from WMO and UNESCO, and draws on the international standards of the International Organization for Standardisation. Water Quality Monitoring is companion volume to Water Quality Assessments edited by Deborah Chapman.