## 2 Materials and Methods
### Full-Scale SVE System
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & **Units** & **RL** & **S291** & **S291C** & **S293** & **S293A** & **S293B** & **S037** & **S037A** \\ \hline
**Sampling Depth** & **m** & **-** & **4** & **4** & **4** & **4** & **4** & **4** & **1** \\ \hline
**Humidity at 105 \({}^{\circ}\)C** & \% & - & 32.5 & 21.2 & 8.2 & 17.2 & 12.6 & 15.2 & 5.2 \\
**Residues at 105 \({}^{\circ}\)C** & \% & - & 67.5 & 78.8 & 91.8 & 82.8 & 87.4 & 84.8 & 94.4 \\
**Fraction \textless{} 2 mm** & \% & - & 92.6 & 93.9 & 67.7 & 94.3 & 68.3 & 71 & - \\
**C\textgreater{}12** & mg/kg & 750 & 119.4 & 445.2 & 525 & 404.4 & 406.5 & 658 & 34,177 \\
**C\textless{}12** & mg/kg & 250 & 1156 & 908 & 7108 & 1855 & 569 & 1608 & \textless{}0.1 \\
**Benzene** & mg/kg & 2 & \textless{}0.005 & 0.226 & 0.524 & 7.63 & 1.64 & 1.82 & \textless{}0.001 \\
**Ethylbenzene** & mg/kg & 50 & \textless{}0.005 & 7.59 & 11.3 & 62 & 6.73 & 19.9 & \textless{}0.001 \\
**Xylene** & mg/kg & 50 & \textless{}0.005 & 12.1 & \textless{}0.005 & 184 & 16 & 95.4 & \textless{}0.001 \\ \hline  & **Units** & **RL** & **S037B** & **S037B** & **SP028** & **SP028C** & **P036** & **P036A** & **P036B** \\ \hline
**Sampling depth** & **m** & **-** & **4** & **1** & **5** & **5** & **1** & **3** & **4** \\ \hline
**Humidity at 105 \({}^{\circ}\)C** & \% & - & 17.6 & 6.3 & 21.1 & 17.1 & 14 & 18.2 & 20.8 \\
**Residues at 105 \({}^{\circ}\)C** & \% & - & 82.4 & 93.7 & 78.9 & 82.9 & 86 & 81.8 & 79.2 \\
**Fraction \textless{} 2 mm** & \% & - & - & - & 85.8 & - & 89.8 & - & - \\
**C\textgreater{}12** & mg/kg & 750 & 3642 & 4128 & 749 & 9812 & 0.2 & 52 & 10,026 \\
**C\textless{}12** & mg/kg & 250 & 408 & \textless{}0.1 & 410 & 333 & \textless{}0.1 & 785 & 1276 \\
**Benzene** & mg/kg & 2 & 1.37 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 \\
**Ethylbenzene** & mg/kg & 50 & 24.4 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 \\
**Xylene** & mg/kg & 50 & 99.8 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Soil concentration measurements from the environmental characterization (EC) in 2005. RL: regulation limits. SVE lines is shown and discussed in the results section. The VOC IN sample is where the volatile hydrocarbons enter the granular activated carbon (GAC) units, while the VOC OUT sample represents the gasses leaving the systems, expecting to be low and under the remediation threshold limits. VOCs were measured through a photoionization detector (MiniRAE Lite, RAE Systems by Honeywell) with an accuracy of \(\pm 5\%\) and resolution of 0.1 \(\mu\)g/Nm\({}^{3}\) (Figure 4f). Moreover, VOC samples were collected monthly for laboratory analysis to verify permit vapor treatment requirements. For the monitoring phase, the daily measured parameters were: vacuum/pressure in extraction wells (mbar), gas flow rate in extraction wells and manifolds (m\({}^{3}\)/h), VOC concentrations in extraction wells and treatment system compliance data (\(\mu\)g/Nm\({}^{3}\)), and system data for the maintenance (e.g., temperature (\({}^{\circ}\)C), frequency (Hz), and working hours (h) of vacuum pumps). The monitoring of these parameters was necessary to obtain the hydrocarbon mass removal rates (kg/d), calculated using the Equation (1) [11]:  
\[Mass\,Removal\,Rate=Q\times C\times\frac{273}{T}\times P \tag{1}\]  
where \(Q\) is the measured flow rate in the exhaust stack, \(C\) is the hydrocarbon concentration, \(T\) is the exhaust temperature in Kelvin, and P is the pressure in the exhaust. Moreover, the daily control of the moisture in the condensation water tank was necessary to ensure the system reliability watching for excessive condensation as the groundwater rises and falls with rainfall.