ABSTRACT

This study assesses the surface and groundwater quality for human consumption within the vicinity of Karu abattoir in Abuja. Water samples were collected from three points along Tauga stream, comprising the discharge point, 40meters before (upstream) and after (downstream) the discharge point. Groundwater samples were also collected around the abattoir, comprising the abattoir vicinity (Group A), 60meters from the abattoir (Group B) and 200-300meters from the abattoir (Group C). The water samples were collected for rainy season (July, August, September) and dry season (November, December, January). They were analysed for parameters such as temperature, turbidity, total dissolved solids, total suspended solids, pH, dissolved oxygen, biological oxygen demand, colour, odour, total hardness, electrical conductivity, iron content, nitrate, sulphate, coliform bacteria (Escherich;a coli) and faecal streptococci. Results of the analyses of the surface water shows that after the upstream, the values at the discharge point increases and reduces slightly downstream for parameters such as temperature, turbidity, total dissolved solids, total suspended solids, electrical conductivity, biological oxygen demand, total hardness, nitrate, sulphate, iron content, coliform bacteria and faecal streptococci; the pl{ is more acidic, and there is reduced dissolved oxygen at the discharge point. The colours of the water are darker and the odours are very offensive at the discharge point. Groundwater laboratory analyses shows that the Group A samples have higher values for the same parameters as in the surface water including pH; the values of these parameters reduces progressively in Groups B and C, except for those of dissolved oxygen which are least in Group A and higher in Groups Band C. Values of electrical conductivity and total hardness were incositent. The results therefore indicates that the surface water is polluted, with the discharge point having the highest level of pollution; while the Group A groundwater is more polluted and the pollution reduces progressively with distance to Groups B and C. Results also showed that for most of the parameters, the surface water samples have higher concentrations than the ground-vater samples except for total hardness and sulphate . Statistical analyses using analysis of variance (ANOVA) and paired sample student t-test shows that there is significant variation in the concentration of all the parameters except for temperature in the surface water, and turbidity, conductivity and pH in the groundwater; it also shows that there are no significant seasonal variations in most of the surface and groundwater parameters. However results from laboratory analyses indicate that the concentration of the pollutants in the surface water is higher during the dry season. The compliance level of the surface and groundwater samples with the World Health Organisation (WHO) and the Nigerian Standard for Drinking Water Quality (NSDWQ) recommended values are (43.75%) and (62.5%) respectively. The study therefore concludes that the water is not fit for consumption unless adequately treated. It was therefore recommended that there is the need for the treatment of the abattoir effluents before discharging them into the stream; public awareness and enlightenment on possible impact of pollution from abattoir wastes.