Abstract Iit

DEVELOPMENT OF COASTAL WATER QUALITY INDEX FOR KALPAKKAM, SOUTHEAST COAST OF INDIA USHA NATESAN1, SATPATHY.K.K2, SARGURU.S1 AND DEEPTHI.K1 1

Centre for Environmental Studies, Anna University Chennai, Chennai 600 025, India

2

Environmental and Industrial Safety Section, Safety Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, India Water quality index (WQI) is a weighted average of selected ambient concentrations of pollutants. The water quality index provides a single number (like a grade) that expresses overall water quality at a certain location and time based, on several water quality parameters. This approach was adopted to the coastal waters of Kalpakkam to assess its condition. The water quality was evaluated by comparing the results of the study to the threshold values of water quality. Water quality data to derive an index were collected from the sampling done at six stations during different seasons between 2007 and 2008. Surface and near bottom water samples were collected from five stations selected in close proximity to Madras Atomic Power Station (MAPS), Kalpakkam while the sixth station was located near Kottivakam, near Chennai. Seasonal spatial explicit maps for temperature, pH, salinity, water clarity and nutrients were prepared. These maps were imported into ArcGIS software where data ranges, scales, etc. were added. An index value of 100 and 0 indicate the site is Excellent and Worst respectively. For Kalpakkam, surface water record higher WQI scores than bottom water samples. For surface water, station closer to intake well and Kottivakam score the maximum (56.3) and minimum (42.7) WQI respectively. The bottom water does not show much variation between the maximum and minimum WQI scores, the former being 42 and the latter 49. According to the WQI, coastal waters of Kalpakkam is classified as Good.