International Journal of Earth Sciences and Engineering

Ch. Ramakrishna ¹, Y. Satyanarayana ¹, D. Mallikarjuna Rao ¹, P. V. Sivapullaiah ², L. Vaikunta Rao ³

Affiliations
1 Department of Environmental Studies, GITAM University, Visakhapatnam-530045, A.P, IN
2 Department of Civil Engineering, IISc, Bangalore, IN
3 Department of Chemistry, ITAM University, Visakhapatnam-530045, IN

Abstract

In most towns and cities in India ground water forms to a smaller and larger extent, a part of water distribution system. The quality of water supplied to municipalities, which is a major source of drinking water for most people living in these areas. The groundwater quality depends on many factors such as local geology of the area ground water movement, which is also affected by industrial activity, in the proper sanitary system and in coastal areas by salt-water intrusion. To develop a sustainable water quality management, it is a necessary tool to assess the impact of the above parameters on the ground water quality. Chemical and physical characteristics of ground water determine its usefulness for municipal, commercial, industrial, and agricultural water supplies. Greater Visakhapatnam Municipal area forms an ideal study area to address the effect of various factors affecting the ground water quality. In this work, the study conducted on the effect of salt water intrusion on the ground water in the areas susceptible to salt water intrusion is presented. Greater Visakhapatnam Municipal Corporation is located on the east coast of India. To assess the quality of ground water ten sampling were selected. Seawater intrusion has been assessed using ground water chemistry and ionic ratios. The ionic ratios obtained in pre and post were compared to the standard values of seawater to determine whether sea water influences the aquifers. The values that are considered to be indicative of seawater intrusion are calculated for the study area. The major chemical compositions demonstrated that ionic ratios would be useful to delineate seawater intrusion and these ratios include Na⁺/Cl^-, Ca/Mg, Cl^-/(HCO₃+SO₄) and Cl/TA. All boreholes generally less than 2, indicating the dissolution of silicate minerals, which contributes Calcium and Magnesium to the groundwater. Detailed analyses of ground water parameters have indicated a possible threat of salt-water intrusion to the ground water in the areas closure to coastal line. It is also perceived that recharge from precipitation or other sources are not balanced and this has not compensated the replenishment of groundwater. The salt-water intrusion problem can be controlled by using recharge wells near the areas and scientific way of pumping should be implemented.

Keywords

Coastal Aquifers, Ionic Ratios, Sea Water Intrusion, Water Balancing.

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