## 3 Results
### Rainfall Correlations (Influent and Effluent)  
The values for each wastewater parameter shown in Tables 4 and 5 are discussed below in relation to the rainfall. The rainfall showed varying correlations with the wastewater parameters in both the influent and effluent. For the influent pH, there was a statistically significant moderate negative correlation (r = \(-\)0.619, \(p\) = 0.003), suggesting that, as the rainfall increases, the pH of the incoming water decreases, likely due to the introduction of more acidic rainwater. The influent total phosphorus (P Tot) exhibited a strong negative correlation with the rainfall (r = \(-\)0.714, \(p\) = 0.000), indicating significant reductions in the phosphorus concentrations, likely driven by dilution effects. Similarly, the chemical oxygen demand (COD) in the influent showed a moderate and statistically significant negative correlation with the rainfall (r = \(-\)0.619, \(p\) = 0.003), reflecting reduced levels of organic and chemical pollutants. The biological oxygen demand (BOD\({}_{5}\)) in the influent demonstrated a moderate negative correlation (r = \(-\)0.452, \(p\) = 0.050) which was marginally significant, suggesting a dilution effect on organic matter with increased rainfall. The total suspended solids (TSSs) in the influent exhibited a weak and statistically insignificant negative correlation with the rainfall (r = \(-\)0.214, \(p\) = 0.406), indicating minimal or negligible changes. A strong negative correlation was observed for the levels of nitrogen (N-Total) in the influent (r = \(-\)0.809, \(p\) = 0.000), reflecting significant dilution effects. The levels of ammonium (NH\({}_{4}\)) in the influent also showed a moderate negative correlation with the rainfall (r = \(-\)0.619, \(p\) = 0.003), further supporting the idea that rainfall dilutes incoming pollutants. Effluent parameters also displayed notable correlations with the rainfall. The effluent pH had a moderate negative correlation (r = \(-\)0.476, \(p\) = 0.029), indicating a slight but statistically significant decrease in the pH with increased rainfall. For the total phosphorus (P Tot) in the effluent, the same moderate negative correlation (r = \(-\)0.476, \(p\) = 0.029) suggested reduced phosphorus levels, possibly due to lower influent concentrations or improved removal efficiency during higher rainfall events. The effluent COD showed a statistically significant moderate negative correlation (r = \(-\)0.523, \(p\) = 0.011), indicating a reduced chemical oxygen demand during rainfall periods. The effluent BOD\({}_{5}\) exhibited a weak positive correlation with the rainfall (r = 0.238, \(p\) = 0.292) that was statistically insignificant, suggesting a minimal impact from rainfall. The effluent TSSs displayed a very weak and statistically insignificant positive correlation (r = 0.095, \(p\) = 0.693), indicating no meaningful changes. The nitrogen (N-Total) in the effluent had a strong negative correlation with the rainfall (r = \(-\)0.785, \(p\) = 0.000), suggesting significant reductions in the nitrogen concentrations during higher rainfall. Lastly, the levels of ammonium (NH\({}_{4}\)) in the effluent also showed a moderate negative correlation (r = \(-\)0.619, \(p\) = 0.003), confirming significant reductions linked to increased rainfall. These findings collectively emphasize the influence of rainfall on wastewater parameters, with most pollutants showing reductions in both the influent and effluent during rainy periods, primarily due to dilution effects.