# Operation of Water Supply Systems in the Czech Republic--Risk Analysis
## 3 Results and Discussion
### Risk Analysis
Natural risks and their impact on the drinking water supply are also addressed in the study by [PERSON] and [PERSON]. [17]. Floods as a significant natural hazard for water resources are also mentioned in the study by [PERSON], [PERSON], and [PERSON] [20]. The impacts of climate change and the risks associated with water scarcity are also addressed in a study by [PERSON] [21]. Operator A does not possess its own technical means (it does not have its own tankers or wagons) but can borrow them if necessary. Operators B and C already have their own technical means to provide emergency or substitutive drinking water to the population. The proposed measures to mitigate this risk include interconnecting water supply systems, whereby the water supply from a neighboring system can be used if necessary. Operator B is currently constructing interconnections and has developed drought management plans. Operator C already has interconnected systems and has developed drought scenarios projecting to 2050 with a good risk management set-up. Stockpiling drinking water in households in the recommended quantities belongs to other proposed measures as it is employed in many countries, while this study has developed recommendations for households in the Czech Republic on how to maintain drinking water stocks and how to proceed. The risk of deliberate contamination of the source by pathogens (bacterial, parasitic, and/or viral) was assessed by the expert team as a moderate risk with low probability of incidence, but also as an unpredictable risk. Only Operator C was assessed as having a high probability of detection of this risk as they have standard procedures in place to monitor and detect this risk. * Water treatment The results of the risk analysis for each operator's water treatment are presented in Tables 11-13, yet only risks with an RPN of 20 or higher are shown. The results of the full FMEA method concerning the water treatment for all operators assessed are presented in Supplementary Material File S2. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Possible Risk** & **Possible Risk Consequences** & **Possible Cause** & **Current Precations** & **RPN** & **RPN** \\ \hline \hline
**Power cuts** & Restriction of the water treatment plants’ & 5 & Power cuts due to technical reasons (substation cut of a terrorist act & 3 & No measures & 4 & 60 \\ \hline
**Poor structural building** & Water contamination & 4 & Neglected wall maintenance conditions & 4 & Facility maintenance & 2 & 32 \\ \hline
**Insufficient security of facilities (insufficient fencing, security, and/or electronic system)** & Water contamination & 4 & Deteriorated operating conditions & 3 & No measures & 2 & 24 \\ \hline
**Use of inappropriate chemicals for in inappropriate quantities** & Deterioration of the water, in excess the water cause health problems or death & 4 & Trespassing by unknown (unauthorized) persons & 3 & Security of objects by locks and bars. & 2 & 24 \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Top identified water treatment risks (RPN greater than 20)—Operator A (independent operation). The facilities owned by Operator B are secured, regular monitoring of water quality is carried out, and a risk assessment and management system is in place. The most significant identified water treatment risks (RPN greater than 20) for Operator B are shown in Table 12.  
Operator C's facilities are sufficiently secured and monitored by CCTV, the operator invests in maintenance and modernization of the facilities, uses its own laboratory system, control processes and risk assessments, and management processes are well set up. The most significant identified water treatment risks (RPN greater than 20) for Operator C are shown in Table 13.  
In water treatment, the risks of power outage or failure of electricity supply and the risks of cyber -attacks were assessed as the most significant.