Abstract

Residents of flood infested areas face security threats, not only due to damages on properties, risks of collapse buildings or physical drowning but also from water stress which could be a more damaging and slow killer. Most people depend on groundwater for their source of drinking water. As a result of floods groundwater wells can become highly polluted and stressed due to the draining of pollutants from various sources. Poor water quality spreads disease, causes death and hampers socio-economic progress, especially in densely populated areas. Monitoring of water quality in flood infested heavily populated areas such as Akoka and Bariga is therefore a good security measure towards protecting and saving of lives. In this study eight tap and two well water samples were collected for the determination of the physico-chemical and chemical parameters as well as heavy metals. Heavy metal digestion was carried out using concentrated nitric acid. The samples were analysed for lead, iron, chromium, cadmium, zinc, nickel and arsenic using atomic absorption spectrophotometer (AAS). The results showed that seven tap and one well water samples had low pH values ranging from 3.89 to 4.78, one tap water sample had pH 5.14, and one well water had pH of 7.23 but with high turbidity of 23.40NTU (above recommended value of 10). Hardness values (430 and 455 mg/L) in two tap water samples and one well water (380) exceeded the WHO recommended value (100). Some heavy metals were also higher than safe limits. For instance, only one sample was low in iron 0.12 mL; while seven samples ranged from 4.08 to 11.88 mg/L, highly exceeding WHO safe limits of 0.3 mg/L. Lead concentration (0.049 mg/L) in one location also exceeded the WHO limit of 0.01 mg/L. Chemical parameters like chloride, nitrate and phosphate also exceeded recommended levels.