Assessing the Resilience of Water Supply Systems in Oman By: Dr. Kassim Mana Al Jabri Public Authority for Electricity and Water Sultanate of Oman

AGENDA Problem Statement Aim and Objectives Research Methodology Results of Risk Assessment Evaluation of Resilience Discussion of Research Findings Conclusions

Problem Statement Water supply systems in Oman are exposed to a range of risks, due to both natural and man-made hazards. Natural disasters, especially tropical cyclone such as Gonu in 2007, cause immense damage to water supply systems in Oman. There are also risks to water supplies arising from operational practices, perhaps currently the most important being the water losses problem. This research developed an integrated approach to identify and rank the risks and recommends methods of analysis and assessment to improve the resilience of water supply systems in Oman

Aim and Objectives Aim: To bring an understanding of how resilience to various hazards (natural and manmade) in water supply systems can be developed in the Sultanate of Oman. To developed an integrated approach to identify and rank the risks and recommends methods of analysis and assessment to improve the resilience of water supply systems in Oman Objective: Assessing the resilience of water supply systems in Oman through analysis and assessment of risks, including desalination plants, transmission pipelines and water distribution network, and to determine how these risks may be reduced through effective measures of mitigation.

Research Methodology Research Approach

Risk Assessment Approach Due to the lack of adequate information, semi-quantitative risk assessment approach, namely, Coarse Risk Analysis (CRA) is used for the analysis and assessment of risks for water supply systems in Oman. The scope of the CRA consisted of: Identifying hazardous events related to water supply system. Estimate the probability and consequence for each hazardous event. Ranking the hazardous events with respect to their risk. Determine risk as: Risk = Likelihood × Consequence Assessing the need for risk reduction options. Risk factors were identified, ranked and scored at a stakeholder workshop. CRA is presenting probability as rare, unlikely, possible, likely, certain, and consequence as: minor, major, and severe. The combined categories are inserted in a risk matrix show numeric description of risk ratings.

Likelihoods, Consequences Tables Qualitative Measures of Likelihood Consequence of Hazard Events for Transmission Mains Severity Definition Score A <500 properties without water for 12 hours 1 B <1,000 properties without water for 12 hours or one industrial customer <500 properties without water for 24 hours 2 C <10,000 properties without water for 12 hours or two to ten industrial customers <1,000 properties without water for 24 hours or one industrial customer <500 properties without water for 48 hours 4 D <50,000 properties without water for 12 hours or more than ten industrial customers <10,000 properties without water for 24 hours or two to ten industrial customers <1000 properties without water for 48 hours or one industrial customer <500 properties without water for 2-5 days 8 E 100,000 properties without water for 12 hours or more than one hundred industrial customers <50,000 properties without water for 24 hours or more than ten industrial customers <10,000 properties without water for 48 hours or two to ten industrial customers <1000 properties without water for 2-5 days or one industrial customer <500 properties without water for >5 days 16 Level Description Score 1 One in 50 to 100 years 2 One in 20 to 50 years 3 One in 5 to 20 years 4 One in 1 to 5 years 5 More than one per year Consequence of Event Duration for Desalination Severity Definition Score A < 12 hours partial reduction in treated water production (>34% of design output) 1 B <12 hours loss of treated water production 2 C 12 – 48 hours loss of treated water Production 4 D One sites affected for > 4 days 2 – 7 days loss of treated water production 8 E >7 days loss of treated water production 16

Consequence and Likelihood Categories to Generate Risk Scores Risk Table (Matrix) Consequence and Likelihood Categories to Generate Risk Scores Likelihood Consequences Severity A B C D E Level Score (1) (2) (4) (8) (16) 1 2 4 8 16 32 3 (3) 6 12 24 48 64 5 (5) 10 20 40 80 Risk Score ˂ 6 6-16 ˃ 16 Colour Green Amber Red Risk Rating Minor Major Significant

Results of Risk Assessment Summary of Risks to Al Ghubrah Desalination Plant Item Hazard Hazardous Event Before Control After Control L C Risk Sea Water Quality Feed Water Quality Loss of Production Harmful Algal Blooms 3 16 48 8 24 Jellyfish 2 32 4 Accidental Oil Spills at Sea 12 Operational Oil Spills at Sea Re-circulation causing increased salinity Excessive seawater temperature 1 Main Treatment Process MSF Units Structural Failure of Main Process Unit Power Failure Multiple Units (steam/electricity) Power Failure Single unit (steam/electricity) 5 Loss of Process Performance due to Scaling and Fouling CO2 Plant Structural Failure Mechanical and Electrical Failure Process Performance Failure Chlorine Dosing 64

Results of Risk Assessment Summary of Risks to Great Muscat Water Supply System Hazard Consequence Before Control After Control L C Risk Transmission Mains Burst in main from Barka PS to Seeb Res Loss of supply to Seeb 4 16 64 8 32 Burst in main from Al Ghubrah to Qurm, Wattaya, Loss of supply to much of eastern Greater Muscat Ruwi, Muscat, Mumtaz Res and Al Amirat PS (1000mm) Loss of supply to part of eastern Greater Muscat 5 80 2 10 Ruwi, Muscat, Mumtaz Res and Al Amirat PS (600mm) Burst in main from Al Ghubrah to Bausher Wilayat (Waver, Airport, Ghala, Bousher Res) Pumping stations Pump failure - Barka to Seeb PS Partial loss of supply to Seeb Loss of power - Barka to Seeb PS 1 Failure of control systems - Barka to Seeb PS Pump failure - Ghubrah PS Partial loss of supply to Eastern Gt. Muscat Loss of power - Ghubrah PS Loss of supply to Eastern Gt Muscat 40 Failure of control systems - Ghubrah PS Loss of Supply from Desalination Plant Loss of Supply from Ghubrah DP < 12 hours partial reduction in treated water production (>34% of design output) <12 hours loss of treated water production 12 – 48 hours loss of treated water production 2 – 7 days loss of treated water production >7 days loss of treated water production 3 48 24

Interpretation of Risk Analysis Tables Number of Severe Risks to Water Supply Utilities Utility Stage Number with Severe Risk Before mitigation After mitigation Al Gubrah Desalination Plant Sea Water quality 5 4 Main Treatment process 1 Side wide risk 3 Total 17 Great Muscat Water Supply System Transmission Main Pumping Stations 6 Loss of supply from Desalination Plant 2 13 8

Evaluation of Resilience Translation of Risk Score to Level of Resilience Risk Score Level of Resilience (score) Resilience Ranking 1-5 4 very high 6-15 3 High 16 -32 2 Moderate > 32 1 Low 4 Very high resilience: The risks to the system are very low. 3 High resilience: The risks to the system are acceptable. 2 Moderate resilience: The risks to the system are major. 1 Low resilience: The risks to the system are significant or extreme.

The Level of Resilience for Great Muscat Water Supply System Hazard Consequence Before Control After Control Risk Resilience Score Transmission Mains Burst in main from Barka PS to Seeb Res Loss of supply to Seeb 64 1 32 2 Burst in main from Al Ghubrah to Qurm, Wattaya, Loss of supply to much of eastern Greater Muscat Ruwi, Muscat, Mumtaz Res and Al Amirat PS (1000mm) Loss of supply to part of eastern Greater Muscat 80 10 3 Ruwi, Muscat, Mumtaz Res and Al Amirat PS (600mm) Burst in main from Al Ghubrah to Bausher Wilayat (Waver, Airport, Ghala, Bousher Res) Overall Transmission Mains Resilience Score 1.0 (low) 2.3 (moderate) Pumping Stations Pump failure - Barka to Seeb PS Partial loss of supply to Seeb 16 Loss of power - Barka to Seeb PS 5 4 Failure of control systems - Barka to Seeb PS 8 Pump failure - Ghubrah PS Partial loss of supply to Eastern Gt. Muscat Loss of power - Ghubrah PS Loss of supply to Eastern Gt Muscat 40 Failure of control systems - Ghubrah PS Overall Pumping Stations Resilience Score Loss of Supply from Desalination Plant Loss of Supply from Ghubrah DP < 12 hours partial reduction in treated water production (>34% of design output) <12 hours loss of treated water production 12 – 48 hours loss of treated water production 2 – 7 days loss of treated water production >7 days loss of treated water production 48 24 Overall Loss of Supply from Desalination Plant Resilience Score 1.8 (moderate) 2.6 (high)

The Average Resilience Scores to Water Supply Utilities Utility Stage The Average Resilience Score Before Control After Control Al Gubrah Desalina- tion Plant Sea Water quality 2.3 2.7 Main Treatment process 2.2 2.8 Side wide risk 2.1 2.6 Great Muscat Water Supply System Transmission Main 1.0 Pumping Stations Loss of supply from Desalination Plant 1.8

Discussion of Research Findings It was found that the risks to the main treatment processes of desalination plants can be controlled but the risk due to feed water quality might remain high even after implementing mitigation measures because of oil contamination and harmful algal blooms. The risks associated with the transmission mains and pumping stations are worse compared to those associated with the loss of supply from the desalination plant. The analysis showed that the most severe risks are those associated with pipe rather than pump failure. The research has shown that the resilience of the desalination plants is currently higher than the water supply systems, and the resilience of the transmission mains and pumping station is very low. By implementing mitigation measures the resilience of the water utilities could reach 70%.

Conclusions The financial impact posed by Non-Revenue Water (NRW) was found to be 32% of the total revenue budget. This is high in comparison with international standards. The results emphasize that exceptional events can have a severe impact on water system management. Risk associated with exceptional event is very difficult to assess. The study concluded that resilience of parts of the water system in Oman is low and mitigation measures are certainly needed. The risk assessment process has contributed to an advancement of knowledge which can be applied to water networks in the Middle East and other arid countries.

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