IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) e-ISSN: 2319-2402,p- ISSN: 2319-2399.Volume 11, Issue 9 Ver. I (September. 2017), PP 33-37 www.iosrjournals.org DOI: 10.9790/2402-1109013337 www.iosrjournals.org 33 | Page A Study to assess the water quality of Drinking water by using the physico-chemical and Biological parameters in the areas of Chennai City Veena Gayathri Krishnaswamy and Rita Jayaraj Department of Biotechnology Stella Maris College, Chennai Corresponding author: veenagayathri@yahoo.com --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 28-08-2017 Date of acceptance: 13-09-2017 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Water plays a vital role in human life. The importance of groundwater for existence of human society cannot be overemphasized. There are several states in India where more than 90% populations are dependent on groundwater for drinking and other purpose [1,2]. Most of the industries discharge their effluent without proper treatment into nearby open pits or pass them through unlined channels, resulting in the contamination of groundwater [3]. The incidence of groundwater pollution is highest in urban areas where large volumes of waste are concentrated and discharged into relatively small areas [4]. The hydrogeochemical conditions are also responsible for causing significant variations in groundwater quality[5]. Groundwater pollution (also called groundwater contamination) occurs when pollutants are released to the ground and make their way down into groundwater. It can also occur naturally due to the presence of a minor and unwanted constituent, contaminant or impurity in the groundwater, in which case it is more likely referred to as contamination rather than pollution. Leachate from sanitary landfills can lead to groundwater pollution. It is most commonly used in the context of land-filling of putrescible or industrial waste. Leachate from a landfill varies widely in composition depending on the age of the landfill and the type of waste that it contains.[6] It usually contains both dissolved and suspended material. The generation of leachate is caused principally by precipitation percolating through waste deposited in a landfill. Once in contact with decomposing solid waste, the percolating water becomes contaminated, and if it then flows out of the waste material it is termed leachate. Additional leachate volume is produced during this decomposition of carbonaceous material producing a wide range of other materials including methane, carbon dioxide and a complex mixture of organic acids, aldehydes, alcohols and simple sugars. Groundwater pollution with pathogens and nitrate can also occur from the liquids infiltrating into the ground from on-site sanitation systems such as pit latrines and septic tanks, depending on the population density and the hydrogeological conditions[ 7]. The treated effluent from sewage treatment plants may also reach the aquifer if the effluent is in filtrated or discharged to local surface water bodies. Therefore, those substances that are not removed in conventional sewage treatment plants may reach the groundwater as well. This is because in conventional sewage treatment plants, micro-pollutants such as hormones, pharmaceutical residues and other micro-pollutants contained in urine and feces are only partially removed and the remainder is discharged into surface water, from where it may also reach the groundwater [8] Further causes of groundwater pollution are excessive application of fertilizer or pesticides, chemical spills from commercial or industrial operations, chemical spills occurring during transport (e.g. spillage of diesel fuels), illegal waste dumping, infiltration from urban runoff or mining operations, road salts, de-icing chemicals from airports and even atmospheric contaminants since groundwater is part of the hydrologic cycle. Over application of animal manure may also result in groundwater pollution with pharmaceutical residues. Groundwater is also an alternative source for agricultural and industrial sector. During last decade, it is observed that the groundwater pollution has drastically increased due to human activities. Consequently, number of water borne diseases has also increased among public. Contaminated drinking water is believed to be the cause of various diseases which is on the rise during summer. Water-borne diseases may be of microbial origin such as diarrhoea, dysentery, cholera, and typhoid and chemical origin such as fluorosis and methemoglobinemia. So, basic monitoring of groundwater has necessitated observing the demand and status of groundwater quality. This present study was attempted to carry out qualitative analysis of some physico-chemical and biological parameters of groundwater in the study area of Chennai.