**7. Conclusion**

In Nigeria, the most frequent water sources are surface waters (rivers, streams, ponds and lakes) and groundwater (borehole and hand-dug wells). The physicochemical assessments of water samples showed that while some of the parameters are within permissible limits, many exceeded the stipulated standards. Application of the water quality index (WQI) to determine the suitability of the water for an intended use indicated that most water sources in the western part of the country are good and suitable for human consumption except for incidences of high levels of fecal contamination in some rivers. The WQI for most locations in the northern part of the country is either bad or poor and not suitable for human consumption. In the eastern and southern part of the country, the WQI index indicated marginal quality that was not suitable for human consumption without treatment. This marginal quality could be as a result of the high levels of nitrate and acidic pH of most of the waterbodies in the area. In all, it is recommended that prior treatment of the water is very important before consumption so as to avoid water-borne related diseases and illnesses.
