## 2 Materials and Methods
### Methodology
\begin{table}
\begin{tabular}{c c} \hline
**Parameter** & **L\({}_{\text{i}}\) Value [mg/L]** \\ \hline Pb & 0.100 \\ Cd & 0.005 \\ Ni & 0.020 \\ Cu & 0.200 \\ Fe & 5.000 \\ Zn & 1.000 \\ Cl & 250.000 \\ SO4 & 250.000 \\ NH4 & 1.500 \\ \hline \end{tabular}
\end{table} 
Table 1: Allowable limits of particular parameters. concentration of the immobile parameter. This factor was calculated using the following formula:  
\[\text{EF}=\frac{\frac{\text{CF}_{\text{m}}}{\text{cmi}}}{\frac{\text{CF}_{\text{ b}}}{\text{cbi}}} \tag{3}\]  
where:  
numerator--is the ratio of heavy metal to immobile element in the analyzed sample. denominator--is the ratio of heavy metal to immobile element in the background sample. An index value < 2 suggests minimal enrichment, values between 2 and 5 indicate moderate enrichment, values between 5 and 20 suggest significant enrichment, values between 20 and 40 represent very high enrichment, and a value greater than 40 suggests extremely high enrichment. In various studies, the immobile parameter was taken into account, for example, AI, Fe, Me, Mn, Sc, and Ti [50; 51]. Iron was used as the immobile parameter [52] in this study. The choice of iron as an immobile component was dictated by the fact that it was measured in all piezometers throughout the observation period. The second part of the analysis included the determination of health risk assessment. The risk assessment methodology was prepared based on the guidelines of the US Environmental Protection Agency [53]. For this purpose, the formula for calculating the average daily dose through the ingesting pathway (ADD) [54] was used. ADD was calculated from the following formula:  
\[\text{ADD}=\frac{\text{C-ING-EF-ED}}{\text{BW-AT}}.10^{-6} \tag{4}\]  
where:  
C--is the concentration of the particular parameter in water (\(\text{\mu g/L}\)). ING--is the ingestion rate (mL/day). EF--is the exposure frequency in days/years. ED--is the exposure duration in years. BW--is the body weight (kg). AT--is the average exposure time in days. It should be noted that for the analyzed area of research, only an analysis of drinking water was carried out. Statistical data for Poland was used in the analysis. It was assumed that the inhabitants of the city of Tychy would use only groundwater from this area. The data for the P16 piezometer (located at the inflow of water to the landfill) and for the P9 and P10 piezometers (located at the outflow) were taken into account. The choice of these piezometers was dictated by the fact that, in their technical design, the filter is present on the entire thickness of the aquifer [10]. The input data for the calculation were assumed to be an average female weight of 70 kg and an average male weight of 85 kg [55]. It was also assumed that a woman drinks an average of 1.6 L of water, and a man 2 L per day. These numbers were averaged, and the ING value was 1800 mL and the BW value was 77.5 kg. It was assumed that a person lives an average of 80 years, consumes water with these properties, and drinks it 365 days a year. The above equation was used to calculate the A Hazard Quotient (HQ). This is an indicator that uses the relationship between ADD and Reference Dose (RfD), i.e., the maximum permissible daily exposure level for humans [56]. \[\text{HQ}=\frac{\text{ADD}}{\text{RfD}} \tag{5}\]  
RfD values were determined based on the Integrated Risk Information System (IRIS) of the U.S. EPA. Such data do not exist for all the parameters described. There are no such values for chlorides and sulfates. The remaining values are summarized in Table 2.  
Values of this indicator which do not exceed 1 prove that there is no risk. Cumulative risk resulting from exposure to several parameters is found by adding the HQ values to obtain a Hazard Index HI [57]. All the monitoring results taken into account were taken from annual reports. Chemical analyses were performed in accredited laboratories.