Abstract
The river Yamuna has become a waste water reservoir due to the disposal of municipal and industrial waste into the river. Most of the water treatment plants are either not working at all or they are overloaded for their respective capacities. Yamuna is the main source for the replenishment of ground water in the study area. Hence the assessment of ground water quality seems to be essential. The present study is confined to evaluate the groundwater quality of central and southeast districts of NCT of Delhi. In this study, arithmetic weighted water quality index (WQI) method is applied for analysing the quality of groundwater. Spatial interpolation model was applied to depict the groundwater quality potentiality map of the area. The results so obtained reveal that the groundwater of the study area is completely unpotable for drinking as well as for other domestic usage without proper treatment because maximum part of the study area exhibits a very high WQI value.