Groundwater Quality Zoning in the Perspective of Health Hazards

Groundwater quality assessment with respect to natural chemical constituents is extremely important for checking health hazard risk. Information on spatial variation and level of anomalous concentration is crucial also for management of the available water resources. In the present study an attempt is made using geographic information systems (GIS) to identify and demarcate zones and levels of pollution. Groundwater quality zoning is carried out based on spatial analysis of groundwater quality data acquired from 51 wells of three administrative blocks of Udaipur district, Rajasthan (India). Concentrations of various natural chemical constituents of groundwater in the study area have been compared with the guidelines of the Bureau of Indian Standards (BIS) and the World Health Organisation (WHO) for drinking water and irrigation water. The study has revealed that groundwater in many parts of the region is unsuitable either for drinking or for irrigation. Extreme high concentrations of hardness, fluoride, nitrate and calcium are observed in different parts of all the three administrative blocks. Mineralogy of the vadose zone and aquifer formations appear to be the chief controller of the groundwater quality. However, land-use/ land-cover and agricultural practices such as use of fertilisers and pesticides may also have significant influence on the groundwater quality. Forest residue and solid waste may also influence the water quality of the wells located in the forest.