This volume is an analytical summary and a critical synthesis of research at the International Water Management Institute over the past decade under its evolving research paradigm known popularly as 'more crop per drop'. The research synthesized here covers the full range of issues falling in the larger canvas of water-food-health-environment interface. Besides its immediate role in sharing knowledge with the research, donor, and policy communities, this volume also has a larger purpose of promoting a new way of looking at the water issues within the broader development context of food, livelihood, health and environmental challenges. More crop per drop: Revisiting a research paradigm contrasts the acquired wisdom and fresh thinking on some of the most challenging water issues of our times. It describes new tools, approaches, and methodologies and also illustrates them with practical application both from a global perspective and within the local and regional contexts of Asia and Africa. Since this volume brings together all major research works of IWMI, including an almost exhaustive list of citations, in one single set of pages, it is very valuable not only as a reference material for researchers and students but also as a policy tool for decision-makers and development agencies.

Arsenic in drinking water derived from groundwater is arguably the biggest environmental chemical human health risk known at the present time, with well over 100,000,000 people around the world being exposed. Monitoring the hazard, assessing exposure and health risks and implementing effective remediation are therefore key tasks for organisations and individuals with responsibilities related to the supply of safe, clean drinking water. Best Practice Guide on the Control of Arsenic in Drinking Water, covering aspects of hazard distribution, exposure, health impacts, biomonitoring and remediation, including social and economic issues, is therefore a very timely contribution to disseminating useful knowledge in this area. The volume contains 10 short reviews of key aspects of this issue, supplemented by a further 14 case studies, each of which focusses on a particular area or technological or other practice, and written by leading experts in the field. Detailed selective reference lists provide pointers to more detailed guidance on relevant practice. The volume includes coverage of (i) arsenic hazard in groundwater and exposure routes to humans, including case studies in USA, SE Asia and UK; (ii) health impacts arising from exposure to arsenic in drinking water and biomonitoring approaches; (iii) developments in the nature of regulation of arsenic in drinking water; (iv) sampling and monitoring of arsenic, including novel methodologies; (v) approaches to remediation, particularly in the context of water safety planning, and including case studies from the USA, Italy, Poland and Bangladesh; and (vi) socio-economic aspects of remediation, including non-market valuation methods and local community engagement.

This guidebook provides theoretical and practical information for using a variety of isotope tracers for dating old groundwater, i.e. water stored in geological formations for periods ranging from about 1000 to one million years. Theoretical underpinnings of the methods and guidelines for their use in different hydrogeological environments are described. The guidebook also presents a number of case studies providing insight into how various isotopes have been used in aquifers around the world. The methods, findings and conclusions presented in this publication will enable students and practicing groundwater scientists to evaluate the use of isotope dating tools for specific issues related to the assessment and management of groundwater resources. In addition, the guidebook will be of use to the scientific community interested in issues related to radioactive waste disposal in geological repositories.