IJSRD - International Journal for Scientific Research & Development| Vol. 5, Issue 08, 2017 | ISSN (online): 2321-0613 Study of the Movement of Saline Water into Freshwater Aquifers Raghu Samenani1 Lavanya Punnam2 Pavani Sasndra3 1,2,3Assistant Professor 1,2,3Department of Civil Engineering 1,2,3Nadimpalli Satyanarayana Raju Institute of Technology, Visakhapatnam, India Abstract— Saline water is the most common pollutant in fresh total dissolved solids, Conductivity, calcium, magnesium ground water. Saline water intrusion occurs where saline and Salinity water displaces or mixes with fresh water in an aquifer. The To identify Principal pollutants using Nemerow’s phenomenon can occur in deep aquifers with the upward Pollution index. advance of saline waters of geologic origin, in shallow To assess the water quality and delineate the areas where aquifers from an invasion of sea water. Intrusion of saline saltwater is present in the various coastal water-bearing water into heavily exploited aquifers is a serious problem that zones of the Vishakhapatnam aquifer system occurs in the coastal areas. Salt water intrusion into fresh To interpret the quality and thus it’s suitability for groundwater formations generally results inadvertently from drinking. activities of man and natural causes. Coastal zones are among the most densely populated areas in the world. These regions B. Materials & Methods face serious hydrological problems such as scarcity of fresh 1) Estimation of Physico-Chemical Parameter: water, contamination of groundwater and seawater intrusion. The water samples are collected from bore wells in the areas The growth in global population and raising standards of from Ramakrishna beach area to Lawson bay colony area of living have increased water demands and pumping from Visakhapatnam. The collected samples are properly labeled aquifers. Excessive pumping has led to a dramatic increase in indicating the source of the sample time and date of the saltwater intrusion problems. Visakhapatnam is a fast collection the samples are brought to the laboratory and growing city with rapid increase of population, (12, 98,896) analyzed the parameters from standard tests (Kumara Swamy 2011 Census. The water available to city is only through N)(10) lab manual (table: 3.2) within 48 hours of collection. Megahdri gedda reservoir and Tatipudi reservoir. This water Values of these parameters are used to determine Water does not fulfill the requirement of city usage. So the ground Quality Index and Nemerow’s pollution index water has become an important source but this ground water a) pH is being over abstracted and may result in salt water intrusion. The electrodes are calibrated with two standard buffer The groundwater samples are collected from the four solutions of pH 4.0 and 9.2 (A buffer is a solution offering different areas along the coast. These samples are analyzed resistance to change in pH and whose pH value is known). for standard tests like pH, conductivity, calcium, magnesium, The sample temperature is determined at the same time and chloride, total dissolved solids, total hardness and salinity. is entered into the meter. The electrode(s) are rinsed Through these tests quality of ground water in these areas is thoroughly with deionised distilled water and carefully wiped determined and the possible occurrence of salinity intrusion with a tissue paper. Electrode is dipped into the sample is studied the present studies are to observe the salt water solution, solution swirled and after minute reading is taken. intrusion conditions of the selected points and to assess The reading is taken after the indicated value remains freshness of water in order to check its potability. From four constant for about a minute. areas, fifteen samples are examined from Rama Krishna b) Electrical Conductivity beach area to Lawson bay Colony area. Electrical conductivity is the ability of water to allow electric Key words: Saline Water, Water Quality Analysis, Physio- current through it is and is expressed in micro mhos per Chemical Properties centimeter (µ mhos/cm). E.C of water indicates whether the water is polluted with electrolytes (dissolved mineral I. INTRODUCTION contents) or not. Generally E.C is determined at 250C by Saline water is the most common pollutant in fresh ground conductivity meter. A rapid estimation of total dissolved water. Saline water intrusion occurs where saline water solids content in water is obtained by EC. displaces or mixes with fresh water in an aquifer. The c) Total Dissolved Solids phenomenon can occur in deep aquifers with the upward A clean porcelain dish is ignited in a muffle furnace and after advance of saline waters of geologic origin, in shallow partial cooling in the air; it is cooled in a desiccators and aquifers from an invasion of sea water. Intrusion of saline weighed. A 100ml of well mixed sample (graduated cylinder is rinsed to ensure transfer of all suspended matter) is placed water into heavily exploited aquifers is a serious problem that 0 occurs in the coastal areas. Salt water intrusion into fresh in the dish and evaporated at 100 C on water bath, followed by drying in oven at 1030C for 1 hour. Drying to a constant groundwater formations generally results inadvertently from 0 activities of man and natural causes. weight at 103 C, cooled in desiccators and weighed. Total solids (mg/l) = (A-B) * 1000 / V A. The Objectives A = Final weight of the dish in mg. Thus the objectives are B = Initial weight of the dish in mg. To analyze the groundwater samples for eightphysio- V= Volume of sample taken in ml. chemical properties such as pH, chloride, total hardness, All rights reserved by www.ijsrd.com 727 Study of the Movement of Saline Water into Freshwater Aquifers (IJSRD/Vol. 5/Issue 08/2017/194) d) Chlorides V.V. Jagannadha Sarma et al., (2006) conducted a 25 ml of sample is taken in a conical flask. 1 ml of potassium study on the quality of groundwater from 250 open wells in chromate is added to get light yellow colour. Titrated with the coastal aquifer of Kaniti-Paravada near Visakhapatnam, standard silver nitrate solution till colour changes from India. The study brings out the fact that the occurrence of yellow to brick red. The volume of silver nitrate added (V) is highly brackish waters in certain localized pockets is due to noted. the hydrogeological processes going on in the area and not Chloride in (mg/l) = V * normality of AgNO3 * 35.46 *1000 due to the influence of the sea. The phenomenon is verified / volume of sample taken. by determining standard ratios of tracing sea-water Where normality of AgNO3 = 0.028 contamination like Ca/Mg, Cl/HC03 and Ta/Th. Conductivity V = Volume of silver nitrate required for sample and sodium adsorportion ratio are also determined for finding e) Total Hardness out the alkali hazard, to supplement the observation. 25ml of sample is taken in a conical flask. 1-2 ml buffer solution is added followed by adding 2 drops of Eri Chrome III. METHODOLOGY black t and titrated with standard EDTA (0.01M) till wine-red Vishakhapatnam is situated on east coast of India mid-way colour changes to blue. The volume of EDTA required (V) between Chennai and Kolkata. It is included between the is noted. north latitudes 170 38’ and 170 50’ and east longitudes 830 16’ Total hardness (mg/l) = V * 1000 / volume of sample taken. and 830 21’ from Rushikonda on north of Vishakhapatnam Where V = Volume of EDTA required for sample. up to Dolphin Nose in the south. It is like a small basin f) Calcium surrounded by hills on three sides, on the northern side is the 50 ml of sample is taken in a conical flask and about 2 ml of Kailasa hill range with average height of 270m and on the NaOH is added to give a pH of 12 to 13. While stirring about south side is Yarada Hill range with an average height of 0.2 grams of the Murexide indicator is added. Titrated against 330m above sea level. The general conditions of the climate EDTA slowly until the colour of the solution turns from pink offer hardly any seasonal variations. The temperature varies to purple at the end point. Ensure that further addition of 1 or from 250 C to 340 C. The annual rainfall being 98 cm is a 2 drops EDTA does not change the colour further. measure amount of which is contributed by south-west Calcium hardness (mg/l) as CaCO3 = V * 1000 / ml of sample. monsoon Where V = Volume of EDTA used by sample. g) Magnesium A. Data collection: Magnesium hardness = Total hardness – Calcium hardness During the present study fifteen main points in the stretch of h) Salinity about four kilo-meters are taken from areas near the coast line It is defined as the total solids in water after all carbonates i.e. near Rama Krishna beach, Pandurangapuram, East point have been converted to oxides, all bromides and iodides have colony, Appughar, Lawson’s bay colony, are selected for been replaced by chlorides and all organic matter has been sampling. Water samples are collected from bore wells from oxidized. The salinity was tested by using the instrument YSI these locations and analyzed using the standard tests in order Model 85 Handheld oxygen, conductivity, Salinity and to know the salt water intrusion into the aquifers near to the temperature system. The YSI Model 85 probe is a non- coast line and assess its freshness and potability detachable, combination sensors designed specifically for Location of sample Sample No this system. The conductivity portion is a four electrode cell Rama Krishna beach with a cell constant of 5.0/cm+4%. The dissolved oxygen Sample No Beside kali matha temple portion is a polar graphic Clark type sensor.