Analysis of Groundwater Quality in Bauchi Metropolis (Nigeria) and interpretation using GIS

Abstract

Fresh water resources include groundwater as a crucial component. It is essential to meeting the water needs of the country's diverse users and sectors. If the water quality is not evaluated, the usage and sustainability of the natural resources cannot be ensured. This study deals with the analysis of ground water quality in Bauchi metropolis and interpretation using ArcGIS according to the inverse distance weighting (IDW) technique. Water samples were taken from 18 hand dug wells randomly selected from six districts to assess for both bacteriological and physiochemical parameters. The bacteriological parameter tested for was Total Coliform Count, while the physiochemical parameters were: pH, Electrical Conductivity, Total Dissolves Solids, Free residual chlorine Cl-, Lead Pb, Total Hardness, Calcium Ca2+ and Magnesium Mg2+ using standard procedures prescribed by American Public Health Association, APHA. The results showed that all samples tested positive to Total Bacteria Count in the laboratory when compared to WHO Standard. whereas samples S3, S4, S5, S6, S7, S8, S12, S13, S14, S16, S17 tested negative to Total Bacteria Count under NSDWQ Standard while the remaining samples tested positive. Sample S10 was the highest at 134 cfu/100ml while S17 was the least at 1 cfu/100ml. Samples S1and S2 were not within the standard recommended pH range. Only sample S7 at 0.60 mg/L tested positive to free chlorine when compared with the NSDWQ guideline value. Sample S6 had the least TDS value of 90 mg/L while the highest value of 710 mg/L was recorded for S7. For lead content, Maximum value was recorded as 0.26 mg/L in samples S14 and S15. Sample S2 had the highest calcium value of 1.45 mg/L while S14 had the least value of 0.00 mg/L. Maximum value of magnesium was recorded in sample S14 having 3.58 mg/L while the lowest value was recorded in S11 having 0.52 mg/L. All Water samples were within the allowable limits for total hardness and are considered to be soft. It was concluded that samples S6 and S16 conformed to most of the standards while sample S7 did not conform to most of the standards when compared to WHO and NSDWQ.