Microbiological and chemical assessment of spring water from a rural setting in Ondo State Southwest, Nigeria

Assessment of spring water from Ikare-Akoko, a rural setting in southwest, Nigeria for microbial and chemical contaminants was carried out. Total heterotrophic bacteria count of 4.0 x 106 CFU/mL was highest during the peak of the rainy season in Omi-idu spring (Igbede community) while the lowest population of 0.14 x106 CFU/mL was in Agadagidi spring (Ishakunmi community). The highest coliform population of 2.8 x 106 CFU/mL was at Isunpaiye (Oyinmo community), while the lowest value of 0.19 x106 CFU/mL was recorded at Agadagidi (Ishakunmi). The multiple tube fermentation technique was employed to determine the most probable number (MPN) of coliforms per 100 mL of water sample. The highest MPN/100 mL value of 76 ± 2.1 for coliforms was recorded at Isunpaiye while the lowest value of 5.1 ± 2.1 was in Agadagidi spring. Physico-chemical properties of the spring waters were mostly within the WHO benchmark for potable water. Arae had the highest total dissolved solids (TDS) value of 969 mgL-1 (benchmark, 500 mg/L), total hardness values were normal except at Arae (260 mg/L). Heavy metals levels in the spring water were generally low except in Omi-idu spring.Key words: Rural setting, spring water, heterotrophic bacteria, coliform bacteria, physico-chemical properties, heavy metals