Volume No. 7 Issue No.: 2 Page No.: 607-621 Oct. - Dec. 2012

 

ASSESSMENT OF WATER QUALITY INDEX FOR THE GROUND WATER WITH RESPECT TO SALT WATER INTRUSION AT COASTAL REGION OF SURAT CITY, GUJARAT, INDIA

 

Desai B. and Desai H.*

Tifac Centre of Relevance and Excellence in Environmental Engineering, Sarvajanik College of Engineering and Technology, Surat (INDIA)

 

Received on : July 10, 2012

 

ABSTRACT

 

The assessment of ground water quality with respect to salt water intrusion at coastal belt of Surat city, Gujarat, India was the main aim of the study. This study was aimed at using the application of Water Quality Index (WQI) in evaluating the quality of ground water samples (nearer to coastal lines) for public usage. This was done by subjecting the 25 ground water samples collected in the year 2010-11 for comprehensive physicochemical analysis using APHA standard methods of analysis. The WQI for 25 samples ranges from 418.65-2281.15 in winter season and 936.89-2411.65 in summer season. Almost ninety nine percent of the samples exceeded 100, the upper limit of WQI for drinking water. The high value of WQI at these stations has been found to be mainly due to the higher values of iron, total dissolved solids, hardness, fluoride, silica, chloride, COD and salinity in the groundwater. Magnesium and chloride are significantly interrelated and indicates that the hardness of the water is permanent in nature. The present study demonstrated application of water quality index in estimating/understanding the quality of ground water and appeared to be promising in the field of water quality management. The results of the analysis when compared with permissible limits of Indian standards for drinking water indicated that most of all the 25 samples are in severely polluted zone and so the water is not safe for domestic use or drinking purpose and would need further treatment. This may be due to over population and higher usage levels of water and paving of open areas in urban zones, replenishment of ground water is drastically reduced. Indiscriminate exploitation of ground water results in lowering of water table rendering many bore-wells dry. To overcome this situation bore wells are drilled to greater depths. This further lowers the depth of water table and in some areas this leads to higher concentration of hazardous chemicals. The over exploitation of ground water resulted in sea water intrusion thereby rendering the ground water saline. To arrest the decline of water level and degradation of the groundwater-quality the bore-well should be recharged by launching Rain water harvesting structure. Bio shield should be developed at coastal belt.

 

Keywords : Water Quality Index, Salt water intrusion, Bio-shield, Rain water harvesting, Silica

 

 

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