Chapter-III(59-80) - Pollution Control Board, Assam

EIA & RA STUDY FOR NAPHTHA SPLITTER PROJECT AT NUMALIGARH REFINERY LIMITEDBaseline Environmental Status3.8.4.2 Analytical Results of Ground WaterPhysico-chemicals characteristics of six ground water samples from the site collectedduring the study period are presented in Tables 3.41 and 3.42. The ground water samplescollected from the above locations show wide variations with respect to almost all theparameters.Table - 3.40SUMMARY OF CHARACTERISTICS OF GROUND WATER SAMPLESParametersRange of recorded Conc.(Results expressed inmg/l except pH)(Desirable /Permissible Limit)IS: 10500Minimum MaximumpH 6.2 7.1 6.5-8.5Total Dissolved Solids 128 238 500/2000Total Alkalinity as CaCO 3 44 124 200/600Total Hardness as CaCO 3 40 88 300/600Calcium Hardness as Ca 8 20 75/200Chloride as Cl 8 16 250/1000Sulphate as SO 4 30 75 200/400Iron as Fe 0.65 2.1 0.3/1.03.8.5 DiscussionThe concentration of iron in all ground water samples exceeds the desirable as well aspermissible limits of Drinking Water Standard IS: 10500. All the other parameters such aspH, TDS, Alkalinity, Hardness, Chloride are well below the specified limits of drinking waterstandard IS: 10500.Conclusion: The analysis results of ground water samples collected from differentlocations reveals that ground water is suitable for domestic, irrigation and industrialpurposes. Ground water from shallow aquifer has slightly higher pH whereas ground waterfrom deeper aquifer is slightly acidic in nature. The high concentration of iron beyondpermissible limit in ground water has been found in some areas, which can be lowered byaeration and filtration method. However, NRL doesn’t use ground water for any purpose.Projects & Development India Limited, Sindri Page 61 of 80