46-Iron Toxicity in Groundwater of Greater Guwahati, Assam

Abstract

Ground water samples from twenty three observation wells, representing the shallow unconfined aquifer, were tested in pre and post monsoon period of 1994 and 1995 for detection of iron content in ground water of Guwahati. Oxidation reduction potential (ORP) and pH were also determined during sampling to see the stability field of iron in pH-ORP diagram alongwith depth of ground water table in different observation wells. Study reveals that the concentration of iron in ground water of the area vary from 0.01 to 3.58 ppm and decreases with depth of ground water table. It is established that average iron content in the study area is much more then the WHO desirable limit of 0.1-0.3 ppm in most of the sites.