A systematic study is proposed to assess the quality of drinking water sources. In this perception, water samples were collected from different villages of Koyyalagudem mandal. The study area is abundant with ground water and it is the only source for drinking and Irrigation. Ground water source is considered as the replenishable water source for domestic, agriculture and industrial activities in most of the world. It has certain inherent advantages over surface water. The ground water quality is determined in Koyyalagudem Mandal which lays in the Northern part of West GodariDistrict of Andhra Pradesh. 18 water samples were collected from different villages and studied for various physico-chemical parameter like pH, turbidity, electrical conductivity (EC), total dissolved solids (TDS), total hardness(TH), Total alkalinity(TA) content of calcium (Ca2+),,magnesium (Mg2+), sodium ( Na ), potassium ( K ), Iron (Fe), chloride(Cl-), fluoride (F- ),sulphate (S042-), Nitrite(NO2-), DO, BOD, COD,) were determined. Analysis was carried out pre and post monsoon of 2015 and 2016.The results were compared with ICMR and Indian standards of water quality. stastistical analysis of pre and post monsoon 2015 and water quality index was calculated.

Keywords : Ground water quality Koyyalagudem Mandal, stastistical analysis of pre and post monsoon 2015 and water quality index.