keywords: : Physico-chemical, TDS, EC, COD, W.H.O., Heavy metals
Borehole water was collected from some communities in Edo state to assess the water quality by examining the physicochemical properties of the water. A total of twenty-five (25) such parameters were analysed in order to confirm whether groundwater is safe, pleasant, and usable or not, it is necessary to evaluate its bio physiochemical concentration (mg/l) in relation to the water suitability standard of the World Health Organization (WHO, 2006) and the Federal Environment Protection Agency (FEPA). The methods employed in the study are in accordance to standard procedure and already established procedures. The observed values of different physicochemical parameters were compared with standard values recommended by World Health Organization (W.H.O.) The outcome of the study, shows that the electrical conductivity (EC), pH and the Total dissolved solid (TDS) were all within the acceptable limits by the W.H.O. with a range of 34.0 - 61.0 uS/cm, (6.15 - 7.94) mg/L, (30.5 - 50.0) mg/L respectively. Likewise, the Alkalinity, salinity and chemical oxygen demand (COD) with averages (3.28, 24.64 & 20.40) mg/L accordingly are all within the acceptable limit by W.H.O for quality drinking water. Also the range for the chloride (10.88 - 19.52) mg/L falls within the permissible limit by W.H.O. for quality drinking water in the terms of its chloride content. The cations (K+, Na+, Ca2+ & Mg2+) and anions (SO42-, PO43-, & NO3-) present in the water were all within acceptable limits going by the established standard. Furthermore, the heavy metals in the water (Cd+2, Zn+2, Pb+2, V+3,Mn+2,Cr+6, Cu2+,Ni+2 & As) are all within W.H.O permissible limits with the exception of Zinc which is above the acceptable standard for quality water, thus would require some sort of treatment. The bacteria test reveals the presence of coliform bacteria, although within permissible limits with the exception of borehole samples GW3 & GW5 which have amount coliform, hence the need of a routine treatment. The result of this research portends a groundwater that is relatively potable for drinking with minimal treatment required.