Foreword

Ground water is a major source of drinking water supply and irrigation in different parts of the country. Indiscriminate extraction and contamination of groundwater due to natural geo-genic causes as well as human incursions take their toll through depletion in water availability and deterioration in water quality. Arsenic contamination of groundwater in the deltaic belts of West Bengal and Bangladesh is a glaring case in point. It is attributed to leaching of arsenic from pyrite bearing sub- soil rocky strata through a combination of chemical and microbial reactions. The causative factors as also the nature and extent of arsenic contamination are not yet well known. However, as per available information, as many as 8 districts in West Bengal with more than 5 million people are affected by arsenic contamination of groundwater .

Recognising the severity of the problem, the Government has taken steps to provide arsenic free water to the affected areas. Arsenic removal plants, based on technologies developed by various organisations, have also been installed in these areas.

In this report, an attempt has been made to collate the scientific information available from sporadic studies. The report also contains information on various technologies and plants for arsenic removal. It is the outcome of investigations by a team of my colleagues in the Eastern Zone Office, Kolkata. We are grateful to the subject matter specialists and agencies for their cooperation in bringing out this publication.

We hope, the report will be useful to all concerned and we trust, it will stimulate a concerted programme for groundwater management.