# Water Supply Systems for Settlements with Arsenic-Contaminated Groundwater--Making the Right Choice
## 3 Results and Discussion
### Drinking Water Requirements and Socioeconomic Position of the Investigated Area
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Label**} & \multirow{2}{*}{**Settlement**} & \multirow{2}{*}{**Population**} & \multirow{2}{*}{**Req. Qmax.d.**} & \multicolumn{2}{c}{**Current Situation**} & \multirow{2}{*}{**Treatment**} & \multirow{2}{*}{**Invest.**} \\ \cline{5-6}  & & & **(L/s)** & & **Number of Wells** & **Abstracted Qz (L/s)** & & **Scheme 1** \\ \hline \multicolumn{6}{c}{Municipality of Kanjiza} \\ \hline K0 & Kanjiza & 9871 & 33.4 & 9 & 22.0 & D & 1,550,000 \\ K1 & Velebit & 277 & 0.9 & 1 & 1.0 & B & 74,000 \\ K2 & Doline & 390 & 1.2 & 2 & 0.5 & B & 110,500 \\ K3 & Zimonjić & 244 & 0.8 & 1 & 0.5 & D & 75,500 \\ K4 & Male Pijace & 1811 & 5.6 & 3 & 2.5 & D & 395,500 \\ K5 & Mali Pesak & 94 & 0.3 & 1 & 0.5 & D & 75,500 \\ K6 & Martonos & 1988 & 6.1 & 2 & 2.0 & B & 307,500 \\ K7 & Novo Selo & 157 & 0.5 & 1 & 0.5 & D & 75,500 \\ K8 & Orom & 1423 & 4.4 & 3 & 2.5 & B & 307,500 \\ K9 & Totovo Selo & 618 & 1.9 & 2 & 2.0 & B & 191,000 \\ K10 & Horgoś & 5709 & 18.8 & 6 & 10.0 & D & 1,210,000 \\ K11 * & Tresnjevac & 1724 & 5.3 & 2 & 2 & B & 307,500 \\ K12 * & Adorjan & 1037 & 3.2 & 1 & 1.5 & E & 244,000 \\ \hline \multicolumn{6}{c}{Municipality of Senta} \\ \hline S0 & Senta & 18,704 & 66.8 & 7 & 45 & F & 3,076,100 \\ S1 & Bogaroś & 568 & 1.8 & 1 & 1 & D & 260,900 \\ S2 & Gornji Breg & 1726 & 5.5 & 1 & 3 & C & 397,050 \\ S3 & Kevi & 726 & 2.3 & 1 & 1.5 & D & 260,900 \\ S4 & Tornjos & 1592 & 5.0 & 4 & 2 & D & 395,650 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Water requirements and current water supply situation in the settlements analysed. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multirow{2}{*}{**Unit**} & \multicolumn{2}{c}{**Municipality**} & \multirow{2}{*}{**MAC**} \\ \cline{3-3} \cline{5-6}  & & **Kanjiza** & & **Senta** \\ \hline As & \(\mu\)g/L & 49.0 & 90.2 & 10 \\ Ammonia & mg N/L & 1.08 & 0.74 & * 0.5 \\ Oxidisability & mg KMnO4/L & 16.6 & 20.0 & 20 \\ TOC & mg C/L & 3.23 & 3.93 & NR * \\ Na & mg/L & 127 & 134 & 200 \\ Fe & mg/L & 0.30 & 3.29 & 0.3 \\ Mn & mg/L & 0.04 & 0.04 & 0.05 \\ \hline \hline \end{tabular}  
* For the waterworks serving up to 5000 EC, the MAC is 1 mg/L. MAC—maximum allowable concentration; NR—not subject to regulation [10].  
\end{table} 
Table 3: Groundwater quality in the major settlements in Kanjiza and Senta. The municipality of Kanjiza consists of thirteen settlements with a total population of 23,039 inhabitants. The smallest settlement has only 94 inhabitants, and the largest one is the town of Kanjiza with 9871 inhabitants. The area of the municipality is 399 km\({}^{2}\). All settlements in the municipality have an organised water supply with basic disinfection. The average exploitation of groundwater for the needs of the municipality is approximately 45 L/s. The municipality of Senta consists of five settlements with a total population of 21,120 inhabitants. The area of the municipality is 294 km\({}^{2}\). All settlements in the municipality have an organised water supply. The average exploitation of groundwater supply for the needs of the municipality is approximately 55 L/s. Note that there is an additional issue in Velebit, Zimonjic, Mali Pesak, Novo Selo, Adorjan, Bogaros, Gornig Breg, Kevi, and Sanad. These communities are all currently supplied from just one well each. This lack of redundancy greatly increases the risk that these settlements will experience extended periods with no water supply, as the single wells may fail, and certainly require downtime for regular maintenance. Figure 4 shows the water requirements and abstraction data graphically. There is a significant disparity between water requirements and the amount of water currently extracted in Kanjiza, which implies that the installed well capacity there is currently inadequate. On the other hand, taken as a whole, Senta municipality has a surplus of water, although, as detailed below, it is of generally low quality.