ASSESSMENT OF WATER QUALITY OF SOME DOMESTIC BOREHOLES IN BAYELSA STATE

ABSTRACT

The water supply to communities and households in the coastal state of Bayelsa in Nigeria is mainly from boreholes. The knowledge of the quality characteristics of water supplied by boreholes is important especially due to such concerns as high urbanization and industrialization rate, crude oil exploitation activities, salt water intrusion in coastal aquifers, bacterial pollution activities and others. In this study, the water quality characteristics of 12 boreholes located in 5 communities in Bayelsa state were assessed for physico-chemical qualities characteristics using standard analytical methods and by means of pollution index and water quality index. From the results, it was observed that; compared to the World Health Organization (WHO) Standards, temperature values are within acceptable limits, pH are generally out of range, turbidity values are greater than 5 NTU, Electrical conductivity (EC) are within WHO guidelines, Manganese (Mn) are greater than WHO limits, Iron (Fe) are generally higher than WHO limits, Lead (Pb), Chromium (Cr), Cadmium (Cd), Nickel, Zinc (Zn) Mercury (Hg) levels are all largely below WHO threshold of 1.0mg/L, The Mean values for pollution index for Iron (Fe) concentration in borehole water are between 0.957 and 3.4925mg/L. These values exceeded WHO values of 1.0mg/L except sample B with mean value of 0.957mg/L. Pollution index was also used to measure the level of contamination of the water based on pH, turbidity, TDS and conductivity. The various values obtained indicate that the water obtained from the boreholes are not adequate for domestic use during wet and dry season without necessary treatment. It is therefore recommended that water to be supplied from boreholes in the studied communities should be treated before supply to prevent water borne diseases and to enhance public health.