Assessment of Underground Water Quality of Gosa Landfill Site of the Federal Capital Territory, Abuja Nigeria

Increasing urbanization results in an increased generation of waste materials and landfills become the most convenient way of disposal. Most of these landfills are mere “holes in the ground” and do not qualify as sanitary means of solid waste disposal. Wastes placed in landfills or open dumps are subjected to either groundwater underflow or filtration from precipitation, resulting to underground water pollution. The study assessed underground water quality of gosa landfill site of the federal capital territory, Abuja Nigeria. It made use of primary data. primary data consist of water samples from the selected wells in the study area. Simple random sampling was used to select wells and boreholes in the study area. Three boreholes and three wells were selected from three communities (Hulumi, Jiyita and Paipe community) surrounding the landfill while one borehole and one well was selected within the landfill making a total of eight (8) water samples. Samples were stored in clean, sterilized, plastic bottles that were rinsed thoroughly with the samples at the collection point before actual collection. The values of total chlorine (2.19mg/l and 5.04 mg/l), phosphate (6.3 mg/l and 9 mg/l), nitrate (21.8 mg/l and 47.4 mg/l), nitrite (1.08 mg/l for well), total iron (2.7 mg/l and 1.68 mg/l) and lead (1.99 mg/l and 1.08 mg/l) for borehole and well respectively of the dumpsite are above safety standard set by Federal Ministry of Environment (fme). The value of dissolved oxygen in borehole of Hulumi (7.82mg/l) well of dumpsite (7.51mg/l), borehole of Jiyita (7.82) and borehole of Paipe (7.57mg/l) are above the safety standard set by fme of 7.5mg/l. The value of chlorine, Biological and chemical oxygen demand and recorded at all sampling points is higher than safety limit set by fme of 0.2mg/l. More also, the value of copper recorded at the borehole and well of Hulumi (1.08mg/l and 1.55mg/l) and Dumpsite (2.83mg/l and 1.3mg/l) are higher than value for safety standard set by fme. Water of all sample sites contains significant amount of total coliform count and Fecal Coliform Count with dumpsite recording highest value of total coliform count of 1600ml and 160ml for well and borehole and fecal coliform count of 6.9 X 102ml and 4.90 X 102ml) for well and borehole respectively. In order to reduce the rate of pollution of underground water quality in the study area construction of boreholes and wells close to septic tanks, latrines and gutters should be prohibited by the respective Government regulatory agencies, the ministry should engage in serious enlightenment campaign to educate the populace on water pollutants, effects and precautions, should in case the residents of the landfill insist in drinking water from wells within the land fill, there should be daily purification of well and borehole water in the study area through biological or chemical processes and there should be a periodic monitoring and assessment of water quality in Gosa landfill to ascertain status at every given time.