AbstractThe impact of gaseous emissions from the ‘E’ flow station on the Oguta Lake ecosystem and its associated tributaries was investigated by measuring gas concentrations over a one year period using digital gas analyzers. These results show that the mean concentrations of SO2, NO2, CO, NH3, H2S and CH4 at the ‘E’ flow station were 16.67, 0.69, 12.33, 2.97 and 4.02ppm respectively, while these concentrations at Oguta Lake were 0.29, 0.25, 5.29, 0.16, 0.3 and 0.9ppm respectively. The results indicate that SO2 and NO2 concentrations at the ‘E’ flow station and Oguta Lake do not meet ambient air quality standards  and thus constitute a threat to the lake and its watershed. Apart from direct health impacts such as respiratory illnesses, poor visibility and aggravation of asthma (which fishermen and other lake users might face), some of these gases (SO2 and NO2) cause the formation of acid rains. The slightly acidic nature of Oguta Lake and its associated tributaries is attributed to gaseous emissions from the nearby ‘E’ flow station and this is inimical to the sustainable development of the lake in terms of water supply, tourism and fisheries development. The use of scrubbers and the construction of a gas re-injection plant at the study area would serve as respectively short and long term remediation measures.
Keywords : Acid rain, Ambient air quality, Gas analyzers, Gas reinjection plant, Scrubbers.