Groundwater Quality Evaluation in Mando and Rigasa Areas, Kaduna, Northwestern Nigeria

The quality of groundwater from twenty (20) hand-dug wells around the Mando and Rigasa areas, Northwestern Nigeria was evaluated in this study. Physico-chemical parameters like pH, EC, TDS, temperature, Na⁺, Ca²⁺, K⁺, Mg²⁺, Fe²⁺, Cl^-, HCO₃^-, NO₃^-, SO₄^2- and faecal coliform count were analysed. The degree of compliance of the various parameters with international guidelines for drinking water quality were determined and the groundwater classified. Comparison of the results of physico-chemical analysis with the NSDWQ and WHO guidelines revealed that most of the parameters in the groundwater had 100 % compliance except for pH, Mg²⁺, NO₃^-, K⁺ and Fe²⁺ with percentage compliance of 80, 90, 75, 70 and 40, respectively. This indicates that some of the groundwater samples are not suitable for drinking purpose. Groundwater quality map based on the Water Quality Index values for the various groundwater sample showed that most parts of the study area have excellent groundwater quality. The faecal coliform bacteria count ranged from 0 CFU/100 ml to too numerous to count. Only two (2) groundwater samples (10%) complied with the 0 CFU/100 ml guidelines of the NSDWQ and WHO, while the rest eighteen (18) groundwater samples (90 %) have faecal coliform bacteria count above the recommended value. Most of the groundwater samples are not suitable for drinking based on the faecal coliform count. The groundwater samples are suitable for agricultural purposes based on the SAR, RSC and PI classifications. The groundwater in the study area is dominated by Na-Cl and CaHCO₃- type facies water.