# Water Quality Monitoring: A Water Quality Dataset from an On-Site Study in Macao
## 4 Data Description
### Data Labeling  
In the water quality monitoring program, the water quality status of each data point is assessed based on the available physical and chemical parameters, and we have introduced authoritative standards in Table 2, such as WHO (World Health Organization), EPA (US Environmental Protection Agency), and the Chinese National Standard [26] which are combined with the local characteristics of the water quality in Macao. This process classifies water quality status into three categories based on real-time values of selected water quality parameters (e.g., pH, turbidity, TDSs, and temperature): compliance with physicochemical criteria, borderline status, and non-compliance with rationalization criteria,as shown in Table 3.  
It is important to note that this classification method is based solely on physicochemical parameters and does not include microbiological or chemical contamination assessments, such as the presence of E. coli or heavy metals. Therefore, a sample classified as \"meets physicochemical criteria\" does not necessarily mean it is safe for drinking without further microbiological monitoring. Figure 12: Turbidity and time. Figure 13: Data online. According to each water quality parameter (pH, turbidity, TDSs, and temperature), its value within the respective threshold rules for the score obtained, and the calculation of the composite score, the formula for calculating the overall score is  
\[\text{Overall Score}=\frac{\text{TDS Score}+\text{pH Score}+\text{Temperature Score}+\text{Turbidity Score}}{4} \tag{4}\]  
This score ranges from 0 to 1, where a higher score indicates better water quality. This score ranges from 0 to 1, where a higher score indicates better compliance with the selected physicochemical parameters. Each data point is assigned a label (Table 4) (meets physicochemical criteria, borderline condition, or does not meet physicochemical criteria) based on the composite score, and the labeled data are saved to a database or output file. Figure 14 shows an example of the original data, and Figure 15 shows an example of the completed data labeling. The dataset used in the analysis is categorized into three classification labels based on the physicochemical parameters of water quality. These labels represent the water quality status as follows:  
* **Meets Physicochemical Criteria (0.5)**: 25% of the dataset. * **Borderline Condition (1)**: 69% of the dataset. * **Does Not Meet Physicochemical Criteria (0)**: 6% of the dataset. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Overall Score** & **Label** & **Explanation** \\ \hline
1.0 & Meets Physicochemical Criteria (1) & Falls within all optimal physicochemical limits. \\
0.5 \(\leq\) Score \textless{} 1.0 & Borderline Condition (0.5) & Partially acceptable but does not fully meet optimal criteria. \\ Score \textless{} 0.5 & Does Not Meet Physicochemical Criteria (0) & Fails to meet the minimum physicochemical standards. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: This is a combined water quality scoring rule table. \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Parameter** & **WHO Guideline** & **EPA Drinking Water Standard** & **GB 5749-2022 (China Standard)** & **Unit** \\ \hline
**pH** & 6.5–8.5 & 6.5–8.5 & 6.5–8.5 & - \\
**TDS** & \textless{}1000 & \textless{}500 (recommended) & \textless{}1000 & mg/L \\
**Turbidity** & \textless{}5 (short-term maximum) & \textless{}1 (95\% sample value) & \textless{}1 & NTU \\
**Temperature** & No strict standard & No strict standard & \textless{}oC \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of International Water Quality Standards for pH, TDSs, turbidity, and temperature.