## 2 Materials and Methods
### Statistical Analysis and Correlation Studies  
Pearson's correlation coefficients (r) and Spearman's rank correlation coefficients (\(\rho\)) were calculated by using Python 3.12.4 to assess the relationships between rainfall, temperature, and various wastewater quality parameters. The correlation matrix provides insights into the linear relationships between variables. The choice of correlation methods was guided by the distribution characteristics of the data and the nature of the relationships between the variables. Each variable was visually assessed using histograms to check for normality. Pearson's correlation is suitable for normally distributed data with linear relationships. It measures the strength and direction of the linear relationship between continuous variables, with the correlation coefficient ranging from \(-1\) to \(+1\). Pearson's values closer to \(+1\) or \(-1\) indicate a strong linear correlation, while values closer to \(0\) suggest a weak correlation. We applied [PERSON]'s correlation to variables like BOD In and TSSs. Out, which were approximately normally distributed based on visual inspection using histograms. To determine the statistical significance of the correlations, \(p\)-values were calculated. A \(p\)-value \(<0.05\) was considered statistically significant, indicating that the observed correlation is unlikely to have occurred by chance. Correlations with \(p\geq 0.05\) were classified as non-significant and reported as such to provide a complete analysis of the data. Where \(p\)-values were above \(0.05\), no significant relationship was observed. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multirow{2}{*}{**Method Used**} & \multirow{2}{*}{**Device Used**} & **Measurement Range** & **Standard** & **Standard** & **Size of Error** & **Based on** \\  & & & **Range (Min-Max) In** & **(Min-Max)** & **(Error Size)** & **(Error Size)** & **Standard** & **Reference** \\  & & & **(mg/L)** & **Out (mg/L)** & **In** & **Out** & **Methods** & **Methods** \\ \hline \multirow{3}{*}{pH} & Method & & & & & & & \\  & 2060\(-\)APAT & pH meter, Glass & & & & & & \\  & 1 RSA CNR & pH Electrode & & & & & & \\  & 29/2003 & & & & & & & \\ \hline \multirow{3}{*}{SST} & Method & Gravimetric method: & & & & & & \\  & 2909\(-\)APAT & FILtrap apparatus, & & & & & & \\  & 1 RSA CNR & oven, Moffin Furnace, & & & & & & \\  & 29/2003 & Analytical balance & & & & & & \\ \hline \multirow{3}{*}{P-Tot} & Method & & & & & & & \\  & 4060\(-\)APAT & Spectrophotometer: 880 & & & & & & \\  & 1 RSA CNR & nm and water bath & & & & & & \\  & 29/2003 & & & & & & & \\ \hline \multirow{3}{*}{NH\({}_{4}\)} & Method & Distillation-titration & & & & & & \\  & 4030\(/\)C\(-\)APAT & technique: Steam & & & & & & \\  & 1 RSA CNR & & Distillation Unit (Buchi & & & & \\  & 29/2003 & & K-355 or equivalent) for ammonia separation. & & & & & \\ \hline Total & Method & Semi-automatic Kjeldahl & & & & & & \\ Nitrogen \& 4060\(-\)APAT & distillation unit: Buchi & & & & & & \\  & 1 RSA CNR & K-355 and A UV-Vis & 26.49–39.86 & & 6.61–8.32 & 4.46 & 0.44 & \(\pm\)5\% of reading & [49; 50] \\ Nitrogen- & 29/2003 \& UNI & Spectrophotometer & & & & & \\  & 1159\(-\)2019 & Shimadzu UV-1800 & & & & & & \\ \hline \multirow{3}{*}{COD} & Method & 5220-D & Closed Reflux, & & & & & \\  & Std & Colorimetric method & & & & & & \\ \hline \multirow{3}{*}{BOD} & Method & 5210-D & Closed Reflux, & & & & & \\  & Std & Colorimetric method & & & & & \\ \hline \multirow{3}{*}{BOD} & Method & 5210-D & Closed Reflux, & & & & & \\  & Std & Colorimetric method & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Analytical methods and standards used for the measurement of wastewater parameters at WWTP Como Acqua. The dataset comprised 8 observations (_n_ = 8), which limits the statistical power and increases the likelihood of non-significant results, especially for weaker correlations.