Groundwater is the only source of drinking water for residents of Puducherry State. This study examines the presence of hazardous ions in the open wells, dug wells and bore wells of Puducherry state. The hazardous ions were determined using standard operating methods for the examination of water. The result of the analysis shows that metals such as pH, TDS, Alkalinity, TDS, Total Hardness, Calcium, Magnesium and Iron were not found in most of the observation water samples, while other traces such as Chloride, Sulpahte, Fluoride and Nitrite are within the permissible limits as prescribed by W.H.O. This study suggests that monitoring of the quality of groundwater should be undertaken regularly to identify the magnitude and source of toxic pollutants, which are responsible for the contamination of groundwater quality in the study area.

Key words: Contamination, Hazardous ions, ground water.