In Ajao Estate, it is believed that poor quality of its groundwater is unconnected to the dislodging of wastewater into the environment by food- and wine-producing industries operating in the area. To ascertain this claim, the impact of this wastewater on microbiological and physicochemical quality of the groundwater was evaluated. Microbiological result of water samples revealed decrease in Staphylococcus aureus, Clostridium spp., Escherichia coli, etc. count from the industrial wastewater dislodging point. Groundwater samples collected from areas under the influence of industrial wastewater showed higher concentration of physicochemical elements than those outside the area of influence (control) except pH (5.96) and Cl (19.80 ppm), while in soil samples, reverse was the case. In groundwater samples, most of the physicochemical parameters were not within the permissible limit for drinking water except zinc (Zn) (0.214 to 1.660 ppm) which falls within World Health and Nigerian limit of 3.0 ppm. The degree of contamination/pollution of all the heavy metals in the soil samples were neither polluted nor contaminated, even though the contamination factor (CF) and geoaccumulation index (I-geo) of cadmium (Cd) was the highest in main soil samples and in control. Negative correlations exist between all the heavy metals in soil samples and those in groundwater except copper (Cu). Reasonable concentrations of all these heavy metals with the exception of manganese (Mn) were seen in the sample of industrial wastewater, suggesting that industrial wastewater may be one of the possible sources of their concentration in groundwater even though there might be other sources.

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Static fatigue tests were conducted on core samples saturated with different phase CO2 to evaluate the fatigue rate and bulk modulus under constant but stepped stress increment. There was re-appearance of primary fatigue at higher stress in all the samples. In the brine saturated sample, for a 4 MPa deviatoric stress increase, there was about 89% increase in primary fatigue rate with up to 16% more strain, up to 88% reduction in fatigue rate when fatigue goes from primary to secondary fatigue and a reduction in primary fatigue duration by 39% with a bulk modulus of 1.050 GPa. Also, the secondary fatigue rate in stress conditions that had the initial primary fatigue portion was up to 16% higher than the secondary fatigue rate for stress conditions that do not have a primary fatigue portion. Saturating the rock with different phase CO2-brine caused a significant change in the fatigue behaviour and bulk modulus depending on the phase of the CO2. While the effect of CO2 phase on bulk modulus is most pronounced in the supercritical CO2 phase (decrease of 22 %), change in fatigue rate is most pronounced on gaseous CO2 phase (an increase of up to 45 %) especially when it is combined with brine (an increase of up to 93 %). The results of this study provide new insights into the deformation and response of rock's bulk moduli to different states of CO2-brine that could exist in a CO2 storage site and will be useful for the future site selection and maintenance of the geological storage projects.