# Water Supply Systems for Settlements with Arsenic-Contaminated Groundwater--Making the Right Choice
## 3 Results and Discussion
### Comparison of the Alternative Approaches  
In order to allow for a direct comparison between the costs for the local approach and the centralised approach, the following tables compare the local supply costs and the centralised supply costs for all of the settlements included within the centralised systems regardless of which municipality they are in. Kanjiza is presented in Table 8, and Senta is presented in Table 9. \begin{table}
\begin{tabular}{l r r r r} \hline \hline  & \multicolumn{2}{c}{**MS Kanjiza System**} & \multicolumn{2}{c}{**MS Senta System**} \\ \cline{2-5}
**Facility** & \begin{tabular}{c} **Investments** \\ **(EUR)** \\ \end{tabular} & \begin{tabular}{c} **Annual Costs** \\ **(EUR/Year)** \\ \end{tabular} & \
\begin{tabular}{c} **Investments** \\ **(EUR)** \\ \end{tabular} &
\begin{tabular}{c} **Annual Costs** \\ **(EUR/Year)** \\ \end{tabular} \\ \hline WTP & 2,078,500 & 172,000 & 2,488,400 & 201,400 \\ Water towers & 1,341,700 & 80,500 & 1,576,800 & 94,600 \\ Pumping pools & 322,500 & 11,300 & 43,000 & 1510 \\ Pumping stations & 37,000 & 115,600 & 323,150 & 128,800 \\ Booster pumps & 2150 & 130 & 16,950 & 1000 \\ Pipelines & 4,708,100 & 211,900 & 5,569,150 & 250,650 \\ \hline
**TOTAL** & **8,759,950** & **591,430** & **10,017,450** & **677,960** \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Estimated value of the central supply for the MS Kanjiza system and for MS Senta. Figure 13: Configuration of the Senta microsystem. Note that to enable a fair comparison to the Kanjiza central system, the local supply approach is presented in Table 7 for all settlements envisaged for connection to the centralised system: Kanjiza, Velebit, Zimonjic, Martonos, and Horgos in Kanjiza municipality and Novi Knezevac. For these settlements then, the value of the investments required for the localised approach is EUR 5,987,500, which is approximately 32% less than the investment required for the centralised system, which amounts to EUR 8,759,950. The absolute difference in investment values is about EUR 2,772,450. In contrast, the annual operating costs are approximately 1.75 times smaller in the central supply alternative for Kanjiza (EUR 591,480/year) than in the local supply alternative (EUR 1,032,000/year). The absolute difference in operating costs is about EUR 440,500 in favour of the centralised system every year. This difference is sufficient to cover the difference in investment in fewer than 10 years, depending on the method of financing. As the depreciation period of drinking water \begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline  & & & \multicolumn{3}{c}{**Investments**} & \multicolumn{3}{c}{**Operating Costs**} \\ \cline{3-8}
**Settlement** & **Population** & **Q Av.D**\({}^{*}\) & & **Total** & **Per Capita** & **Total** & **Per Capita** & **Per m3 of Water** \\ \cline{3-8}  & **m3/d** & **EUR** & **EUR/p.c.** & **EUR/Year** & **EUR/p.c/Year** & **EUR/m3** \\ \hline \hline \multicolumn{8}{l}{**Local supply systems for the 6 settlements in the Kanjiza microsystem**} \\ \multicolumn{8}{l}{Municipality of Kanjiza} \\ Velebit & 277 & 55 & 91,000 & 328 & 7000 & 25.8 & 0.36 \\ Zimonić & 244 & 49 & 91,500 & 375 & 18,500 & 76.8 & 1.05 \\ Kanjiza & 9871 & 1.984 & 2,133,500 & 216 & 381,500 & 38.7 & 0.53 \\ Martonos & 1988 & 379 & 486,500 & 245 & 43,500 & 22.0 & 0.32 \\ Horgos & 5709 & 1.161 & 1,560,500 & 273 & 288,500 & 50.5 & 0.68 \\ Municipality of Novi Knezevac & & & & & & \\ N. Knezevac & 6960 & 1283 & 1,625,500 & 234 & 293,000 & 42.1 & 0.63 \\
**TOTAL** & **25,049** & **4.911** & **5,987,500** & **239** & **1,032,000** & 41.2 & **0.58** \\
**Centralised supply system for the 6 settlements in the Kanjiza microsystem** & & & & & & \\
**TOTAL** & **25,049** & **5773** & **8,759,950** & **350** & **591,480** & **23.6** & **0.28** \\ \hline \hline \multicolumn{8}{l}{\({}^{*}\)Average water supplied/day.} \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Recapitulation—comparison of the approaches for Kanjiza municipality.