Quality Assessment of Groundwater in Abuja, Nigeria for Domestic and Irrigation Purposes

Abstract

Evaluation of the groundwater characteristics in Abuja for household and irrigation purposeswas carried out in this study for both rainy and dry seasons for three consecutive years. The groundwater in the region is alkaline with bicarbonate dominating the major ions. The values of electrical conductivity (EC), total dissolved solids (TDS) and total hardness (TH) were higher in wet season than dry season and it can be attributed to rock-water interaction, dilution, dissolution and chemical weathering. The value of SAR ranged between 0.05 to 0.44 with a mean value of 0.22 for the rainy season and 0.07 to 4.20 with an average value of 1.24 for the rainy season. The mean value of SSP. MAR, RSBC, PI and KR are 37. 95%, 32.21%, 0.31 meq/1, 119.31% and 1.11 meg/l, respectively for the dry season and 39.49%, 33.46%, 0.06meg/l. 72.67% and 0.62meq/l, respectively for the rainy season. The average concentration of TDS, EC and TH in the dry season are 123.50mg/1. 191.28μs/cm and 62.57mg/l while their corresponding values in the rainy season are 224.33mg/1, 300.50ps/cm and 82.32mg/1. Considering on the outcome of the analyses and interpretation of water quality parameters (WQI, SAR, SSP. MAR, RSBC, PI, KR, TH, TDS and EC), the appropriateness of groundwater in Abuja for irrigation purposes is in the order of good to excellent and poor for domestic use due to high nitrate content, which is due to urban pollution. The plotting of the salinity diagram falls within the low salinity zone, which is an indication of low sodic water and further confirms the appropriateness of the groundwater system for irrigation purposes. The variation in the yearly results obtained during the three consecutive years of this study was insignificant which implies that the groundwater chemistry in the locale is fairly constant. characteristic of slightly contaminated groundwater system. Based on the findings, the groundwater in Abuja is suitable for irrigation purposes and poor for domestic purposes.