Evaluation of Groundwater Quality for Drinking and Irrigation in Central Tongu District of the Volta Region of Ghana

摘要

This work was done to assess the physical and chemical qualities of groundwater in some predominantly farming communities in the Central Tongu District of the Volta Region of Ghana. Water samples from 8 boreholes and one hand dug well were assessed for the water quality parameters. The pH of the groundwater samples range between 6.42 to 7.40 with a mean value of 7.07 (±0.33). The pH range fall within the WHO standards for drinking water and within the permissible limit for irrigated agriculture water pH of 6.5 – 9.2. The main hydrochemical facies that has been identified in the study area is the Na - K - HCO 3 water type. Major irrigation water quality parameters assessed included sodium adsorption ratio, residual sodium carbonate, sodium percent and salinity hazard. Results of the irrigation water quality parameters studied showed that water from majority of the boreholes are unsuitable for irrigation. The water samples are salty and hard and only two (2) out of the nine sampling sites representing 22.22% of the samples analyzed met the WHO standard of 500 mg/l CaCO 3 for drinking water and will be safe for drinking.