# Environmental Footprint Assessment of a Cleanup at Hypothetical Contaminated Site
## 5 Results and Discussions  
In Table 3, the summary of environmental footprint of the cleanup under all three scenarios is presented. Figures 5-7 represent the contributions of different elements of the cleanup in environmental footprint in terms of total energy, CO\({}_{2}\) emissions, and NOx, SOx, PM, and HAP emissions, respectively. Table 4 lists the reductions in CO\({}_{2}\), HAP, and NOx, SOx, and PM emissions as a result of renewable energy integration into the remedial system as discussed above in Section 4.3. Figure 4: Steps in footprint methodology (modified from [8]). Figure 5: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Core Element** & & **Metric** & **Unit of Measure** & **Scenario 1** & **Scenario 2** & **Scenario 3** \\ \hline \multirow{8}{*}{**Materials and Waste**} & M\&W-1 & Refined materials used on site & tons & 377 & 377 & 377 \\ \cline{2-6}  & M\&W-2 & Percent of refined materials from recycled or waste material & percent & 33 & 33 & 33 \\ \cline{2-6}  & M\&W-3 & Unrefined materials used on site & tons & 1150 & 1150 & 1150 \\ \cline{2-6}  & M\&W-4 & Percent of unrefined materials from recycled or waste material & percent & 0 & 0 & 0 \\ \cline{2-6}  & M\&W-5 & Onsite hazardous waste generated & tons & 2600 & 2600 & 2600 \\ \cline{2-6}  & M\&W-6 & Onsite non-hazardous waste generated & tons & 0 & 0 & 0 \\ \cline{2-6}  & M\&W-7 & Percent of total potential onsite waste that is recycled or reused & percent & 0 & 0 & 0 \\ \hline \multirow{4}{*}{**Water**} & & Onsite water use (by source) & & & & \\ \cline{2-6}  & W-1 & Source: Groundwater, Purpose: Treatment, Fate: Creek & millions of gallons & 110,000 & 110,000 & 110,000 \\ \hline \multirow{8}{*}{**Energy**} & E-1 & Total energy use & MMBtu & 408,551 & 309,966 & 182,275 \\ \cline{2-6}  & E-2 & Total energy voluntarily derived from renewable resources & & & & \\ \cline{2-6}  & E-2A & - Onsite generation or use and biodiesel use & MMBtu & 0 & 22,526 & 56,315 \\ \cline{2-6}  & E-2B & - Voluntary purchase of renewable electricity & MWh & 0 & 3300 & 6600 \\ \cline{2-6}  & E-2C & - Voluntary purchase of RECs & MWh & 0 & 0 & 0 \\ \hline \multirow{8}{*}{**Air**} & A-1 & Onsite Nov, Sox, and PM emissions & lbs & 55 & 55 & 55 \\ \cline{2-6}  & A-2 & Onsite HAP emissions & lbs & 0 & 0 & 0 \\ \cline{1-1} \cline{2-6}  & A-3 & Total NOx, SOX, and PM emissions & lbs & 219,726 & 155,511 & 69,891 \\ \cline{1-1} \cline{2-6}  & A-4 & Total HAP emissions & lbs & 1119 & 801 & 377 \\ \cline{1-1} \cline{2-6}  & A-5 & Total CHG emissions & tons CO\({}_{2}\)-e & 41,741,757 & 29,609,307 & 13,432,707 \\ \hline \multirow{2}{*}{**Land and Ecosystems**} & & Land and Ecosystem will be disturbed in terms of hazardous waste disposal offsite, depending upon the technique to be used in its disposal.  
\end{table} 
Table 3: Summary of the environmental footprint of cleanup under all scenarios. From Figures 5-7, it can be observed that the greatest contributor to the environmental footprint is the grid electricity used in remedial operations. One reason of this high contribution is the fuel mix of grid electricity in Pakistan. As discussed earlier, Pakistan mostly relies on conventional fossil fuels such as oil and natural gas for electricity generation. SEFA not only takes into account the amount of fossil fuels used in the electricity generation but also considers the energy which is put into the extraction of these fossil fuels. Thus, the higher the use of fossil fuels, the greater will be their contribution in the overall footprint of the remedy. Integration of onsite renewable energy in cleanup helps in the reduction of electricity usage from grid and consequently lowers the energy demand for fuel extraction and electricity transmission as shown in Figure 5b,c. Figure 5: Contributors to the total energy used metric; (**a**) Scenario 1, (**b**) Scenario 2 and (**c**) Scenario 3. Figure 6: _Cont._  
The CO2 emissions are also high in the first scenario, as shown in Figure 6a, owing to the fact that only grid electricity is used in the remediation process.