1. Thomas Pettersson Andreas Lindhe and Lars Rosén Identification and management of risks in water safety planning Decision support method using multi-criteria analysis for WSP Water Safety Conference 2010

2. Water Safety Conference November 2-4 2010, Kuching, Malaysia Presentation outline Mainly present a stepwise (10 steps) procedure for evaluating and comparing risk-reduction options (providing decision support)...but, also incorporate the other tools/methods developed within TECHNEAU 2

3. Water Safety Conference November 2-4 2010, Kuching, Malaysia Background WSP make water utilities to know/understand their system better Awareness of hazards/hazardous events Prioritization of hazards Risk reduction options suggestions But, how to compare different measures? Cost effectiveness? Health risk reduction vs. costs of implemented measures Other benefits... (multi-criteria analysis) Need for applicable tools and method guidance to carry out WSP (provided from the TECHNEAU project) 3

4. Water Safety Conference November 2-4 2010, Kuching, Malaysia Conceptual Structure of the Risk Management Framework and Toolbox in TECHNEAU 4

5. Water Safety Conference November 2-4 2010, Kuching, Malaysia Decision support method in 10 steps 1)Perform a risk ranking (risk identification and estimation, P&C) 2)Identify severe risks (target risks) 3)Identify possible risk-reduction options 4)Estimate risk reduction (new P and C values) 5)Define weights 6)Calculate the benefit of risk reduction 7)Consider additional criteria (cost, environment etc.) 8)Determine the performance (of different criteria) 9)Calculate total performance score 10)Evaluate and compare risk-reduction options 5

6. Water Safety Conference November 2-4 2010, Kuching, Malaysia 6 Step 1: Perform risk ranking Identify hazards and estimate the risk in a risk matrix (here 4x4)

7. Water Safety Conference November 2-4 2010, Kuching, Malaysia 7 Step 1: Perform risk ranking Classes representing relative; Likelihood ( P = 2 (P class -1) ) Severity ( C = 2 (C class -1) ) Calculate the risk as a priority number: R = P x C

8. Water Safety Conference November 2-4 2010, Kuching, Malaysia 8 TECHNEAU Hazard Database

9. Water Safety Conference November 2-4 2010, Kuching, Malaysia 9 12. Future risks The structure of THDB – 12 subsystems

10. Water Safety Conference November 2-4 2010, Kuching, Malaysia 10 Step 1: Perform risk ranking Identified hazards are estimated (P and C) and added in the risk matrix #5 #4 #2 #3 #1 Quality vs. Quantity Risks P: Probability C1: Quality consequences C2: Quantity consequences Risk (R = P x C): R1: Quality risk R2: Quantity risk

11. Water Safety Conference November 2-4 2010, Kuching, Malaysia 11 Step 2: Identify target events The severe events that must be reduced are called target events (Here – Quality risks shown in the matrix) #5 #4 #2 #3 #1 Event#DescriptionPC1C2R1R2 1Pipe burst442168 2Disinfection failure841328 3Raw water contamination282164

12. Water Safety Conference November 2-4 2010, Kuching, Malaysia 12 Step 3: Identify risk-reduction options Probability Consequence Increased risk Preventive options for reduction of probability Reduction of consequences Combination of preventive and consequence reduction options

13. Water Safety Conference November 2-4 2010, Kuching, Malaysia 13 TECHNEAU Risk Reduction Option Database

14. Water Safety Conference November 2-4 2010, Kuching, Malaysia 14 Step 4: Estimate risk reduction Target event Risk Reduction option PP’C1C1’C2C2’R1R1’R2R2’ΔR1ΔR2 11.144412116484124 11.241412116181157 11.34244221688286 k = risk type (e.g. quality and quantity risk) (Target event #1, with three different options) New P and C values are estimated representing the situation after the options are implemented

15. Water Safety Conference November 2-4 2010, Kuching, Malaysia 15 Step 5: Define weights Are the different types of risk (quality vs. quantity) considered equally important or not? Assign weights (v) to define the relative importance between: quality (health) risks and quantity (interruption) risks For example: Quality (1) and quantity (2) risk considered equally important, then v 1 = v 2 = 0.5 Quality risks considered more important then quantity risks, e.g. v 1 = 0.7 and v 2 = 0.3 Use v 1 = v 2 = 0.5 as default values

16. Water Safety Conference November 2-4 2010, Kuching, Malaysia 16 Step 6: Calculate the benefit of risk reduction Benefit - weigh together the two risk reductions B = Benefit of each risk reduction option i = # of risk-reduction option Option B i 1.1 8 (=12 · 0.5 + 4·0.5 = 8) 1.211 (=15 · 0.5 + 7·0.5 =11) 1.3 7 (= 8 · 0.5 + 6·0.5 = 7)

17. Water Safety Conference November 2-4 2010, Kuching, Malaysia 17 Step 7: Additional criteria Additional criteria may be included in the analyses Examples: Costs Environmental effects Goodwill Consumer trust Regulatory complaints...

18. Water Safety Conference November 2-4 2010, Kuching, Malaysia 18 Step 8: Determine the performance Based on the calculated risk reduction, cost, etc., a performance score (s) is calculated by normalising the outcomes Performance score gets a value between 0-1, where 1 is best E.g. risk-reduction and cost (for the three options): Option B i s i1 Cost i s i2 1.1 80.73 20 0.8 1.2111 50 0.5 1.3 70.64100 0 Risk reduction: s i1 = B i / max(B i ) Cost: s i2 = 1-Cost i / max(Cost i )

19. Water Safety Conference November 2-4 2010, Kuching, Malaysia 19 Step 9: Calculate total performance score Total performance score (s i ) of option i i = risk-reduction option w m = Weight determining the relative importance of criterion m (risk, cost, goodwill, etc...) Assume w 1 = w 2 = 0.5 (i.e. risk and cost equally important)

20. Water Safety Conference November 2-4 2010, Kuching, Malaysia 20 Step 10: Summarise results, evaluate and compare risk-reduction options optionBenefit, s i1 Cost, s i2 Score, s i R1R1’R2R2’ 1.10.730.800.77 1.210.500.75 1.30.6400.32 2.1 2.2 2.3 … OK!

21. Water Safety Conference November 2-4 2010, Kuching, Malaysia 21 Testing the decision support method The method has been tested in a case study in Bergen Method also tested in a training seminar in Pretoria (18-19 Oct 2010)

22. Water Safety Conference November 2-4 2010, Kuching, Malaysia 22 Summary and comments Simple but quite powerful method to get an overview of the decision basis (for different control measures) The overall aim is to structure the decision problem and provide transparency This method provides support for a decision, not making decision “Normally, I don’t believe in academic methods since it is too complicated – but this method I will test as soon as I come home (to my water utility)” Stated by a South African water director attending the training seminar

23. Water Safety Conference November 2-4 2010, Kuching, Malaysia 23 RA/RM Publications – TECHNEAU website All publications are found on the TECHNEAU website www.techneau.org under Publications Thank you!