Evaluation of ground water, using water quality index in selected locations of Gashua of Bade LGA, Yobe State, Nigeria

This study was designed to examine physicochemical properties, heavy metals and microbial load of some groundwater (borehole water) at different locations in Gashua Town of Bade Local Government Area of Yobe State, Nigeria. Standard methods were employed to determine physicochemical properties; elemental contents were determined by using Atomic Emission Spectrometer (AES) and the microbial potentials were evaluated by the Pour Plate method. The results indicated that the pH values of 80 % of the water samples from the various sites were within the acidic medium ranges (5.80 to 6.40) which were below WHO, NAFDAC and NSDWQ permissible limit, while 20 % of the samples were within the ranges of 6.49 to 6.80 which falls within the WHO acceptable limit. The presence of heavy metals such as As, Cd, Hg in all the samples were above the required limits, Fe was within WHO and NSDWQ maximum acceptable limits, while Pb was not detected in all the samples. The microbial contamination of the samples with total coliform count indicated 100% of the samples were within the acceptable limits (0.00 to 3.9 CFU/100ml) specified by NSDWQ, samples obtained at Site E, site K, site P and Site R were above WHO maximum acceptable limit, samples obtained from other site(s) indicated E.coli content within the range of 0.00 to 3.0 CFU/100ml which shown only 20% of the samples were above NSDWQ and WHO maximum permissible limit. Other physicochemical parameters such as electrical conductivity (EC), total dissolve solids (TDS), total hardness (TH), nitrate (NO3-), sulphate (SO4-), chloride (Cl-), Magnesium (Mg) and calcium (Ca) within the ranges of 0.06 – 0.25 µs/cm; 0.04-0.13 mg/L; 0.72-1.01 mg/L; 1.99-31.55 mg/L; 13.98-37.61 mg/L; 2.07-24.07 mg/L; 0.13-1.06 mg/L and 0.65-2.59 mg/L respectively. Presence of heavy metals contamination could be attributed to the agricultural activities such as irrigation farming which involved the use of wastewater, chemical fertilizer and other agrochemicals. The activities of traditional potash miners and irrigation farmers warranted littered feacial deposits in the area which could be linked to the bacteriological contamination of some of the water samples.