1 Risks at Komati Water Scheme PED Operations

2CONTENT  Executive Summary  Pump station layout schematic  KWS Maintenance risks  KWS Operational risks  KWS People risks  Risk Rating

3 EXECUTIVE SUMMARY KWS supplies water to Arnot, Hendrina, Duvha and Komati Power stations as well as several mines, municipalities and large farming establishments. Apart from process water to sustain 9000MW the scheme also suppies raw water for domestic purposes for about people. It consists of two large dams (Vygeboom and Nooitgedacht) with four large pump stations supplying water through 400 km pipeline to several reservoirs. The pump stations are unmanned and are controlled via a Process Control System from a control desk near Arnot. Pipeline servitudes go through farming, nature reserves and mining property. Several risks exist

4 Pump station layout

5 KWS Maintenance risks RiskMitigation StrategyBy who/Line of siteBy when 1Loss of both transformers at Wintershoek Pump Station simultaneously or loss of one due to fire, will cut off water to all consumers 1. Provide a spare 20MVA Transformer Dx (Ockie Oosthuizen)When the incident happens 2. Build diversion wall between existing transformers. Dx (Ockie Oosthuizen)Dx unable to provide date 3. Install auto fire fighting system Dx – long term solutionAwaiting feedback from Dx PED/Rotek – short term 21-May Replace with one Bosloop Transformer. Dx (Ockie Oosthuizen)When the incident happens 2 Failure of Switchgear at Wintershoek and Nooitgedacht 1. Inspect, test and maintain regularly. RotekAs per maintenance schedule 2. Spare incomer breakerRotekAvailable 3Loss of Auxiliary Transformers by fire, lightning or protection system 1. Change to “B” unitDx (Ockie Oosthuizen)When the incident happens 2. Run on 100 kVA Diesel generator. RotekAvailable 3. Replace with Bosloop/Vygeboom Transformer. Dx (Ockie Oosthuizen)When the incident happens

6 RiskMitigation StrategyBy who/Line of site By when 4Flash over in switch gear can ignite non flame proof ceiling and roof structure 1. Install non flammable ceiling PED Awaiting feedback from PED 2. Install fire fighting equipment PED Awaiting feedback from PED 5Total failure of Witkloof 132KV network 1. Firm up ring feed supply Dx (Ockie Oosthuizen) Awaiting feedback from Dx 6Failure of Nooitgedacht and Wintershoek suction and discharge lines 1. Operating philosophy to be strictly followed RotekIn place 2. Visual internal line inspection Rotek As per maintenance schedule 3. Spare valves and pipe sections capacity RotekAvailable 7Failure of Hendrina/Duvha pipeline 1. Keep Duvha reservoir as high as possible RotekContinuous/ongoing 2. Naauwpoort pump station on standby Rotek/ Water AffairsWhen reservoir level drops KWS Maintenance risks cont…

7 RiskMitigation StrategyBy who/Line of siteBy when 8Ageing motors at Wintershoek and lower Komati 1. Replacement program PED Wintershoek motors replaced 2. Condition monitoring program Rotek As per maintenance schedule 3. Adherence to operating philosophy RotekContinuous 4. Maintain protection philosophy RotekIn place 5. Vygeboom motors compatible with some of Wintershoek motors RotekAvailable 9Pump Failure1. Provide spares RotekAvailable 2. 50% spare capacity RotekAvailable 3. First line maintenance RotekIn place 10Pipe blow out1. Provide capacity to restore the line RotekAvailable KWS Maintenance risks cont…

8 RiskMitigation StrategyBy who/Line of siteBy when 1Failure of SCADA System 1. Operate manually from pump stations RotekWhen a failure occurs 2. Level and plant monitoring done by non operating staff. RotekPeople available 3. All hard wired protections still operative. RotekIn place 2Aging of operating staff with limited skill transfer to others. 1. Training and development RotekIn place KWS Operational risks cont…

9 KWS people risks cont… RiskMitigation StrategyBy who/Line of siteBy when 1Vandalism and theft of pipelines and valves 1. Develop good relations with land owners who often report failures RotekIn place 2. Pipeline inspection Rotek As per inspection schedule

10 Risk Rating 1 – Low 5 – High RiskImpactProbability Komati Water Scheme 1Loss of transformers52 2Failure of switch gear53 3Loss of auxiliary transformers33 4Fire in breaker room53 5Pump station manifold failure42 6Hendrina/Duvha line failure45 7Ageing of motors35 8Pump failure43 9Pipe Blow out44

11 Risk Rating cont… RiskImpactProbability 10Failure of SCADA system25 11Ageing of operating staff24 12Vandalism and theft35 13Social risk due to loss of supply43

12 END