Study of the Movement of Saline Water into Freshwater Aquifers

Saline water is the most common pollutant in fresh ground water. Saline water intrusion occurs where saline water displaces or mixes with fresh water in an aquifer. The phenomenon can occur in deep aquifers with the upward advance of saline waters of geologic origin, in shallow aquifers from an invasion of sea water. Intrusion of saline water into heavily exploited aquifers is a serious problem that occurs in the coastal areas. Salt water intrusion into fresh groundwater formations generally results inadvertently from activities of man and natural causes. Coastal zones are among the most densely populated areas in the world. These regions face serious hydrological problems such as scarcity of fresh water, contamination of groundwater and seawater intrusion. The growth in global population and raising standards of living have increased water demands and pumping from aquifers. Excessive pumping has led to a dramatic increase in saltwater intrusion problems. Visakhapatnam is a fast growing city with rapid increase of population, (12, 98,896) 2011 Census. The water available to city is only through Megahdri gedda reservoir and Tatipudi reservoir. This water does not fulfill the requirement of city usage. So the ground water has become an important source but this ground water is being over abstracted and may result in salt water intrusion. The groundwater samples are collected from the four different areas along the coast. These samples are analyzed for standard tests like pH, conductivity, calcium, magnesium, chloride, total dissolved solids, total hardness and salinity. Through these tests quality of ground water in these areas is determined and the possible occurrence of salinity intrusion is studied the present studies are to observe the salt water intrusion conditions of the selected points and to assess freshness of water in order to check its potability. From four areas, fifteen samples are examined from Rama Krishna beach area to Lawson bay Colony area.