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Annelie Lourens Dr Jeremy Lucas South Australian Water Corporation Improving System Performance through the process of operational monitoring Water Safety Conference 2010
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Improving System Performance through the process of operational monitoring Context of Experience: Water Safety Conference November 2-4 2010, Kuching, Malaysia
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Improving System Performance through the process of operational monitoring Context of Experience: South Australia Water Safety Conference November 2-4 2010, Kuching, Malaysia
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Improving System Performance through the process of operational monitoring 1.Context of Experience: South Australia Australian Drinking Water Guidelines (ADWG) ADWG Framework 2.Types of monitoring 3.Risk based approach to monitoring Water Safety Conference November 2-4 2010, Kuching, Malaysia
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1.CONTEXT: Water supplied by South Australian Water Corporation Water Safety Conference November 2-4 2010, Kuching, Malaysia Population 1.5 million people 1.1 million metro 0.4 million country 26,000 km of water mains 9,000 km Metro Adelaide 17,000 km Country SA Country SA Populations range from 5 to 600,000
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1.CONTEXT (Cont) South Australian Water Monitoring Program Water Safety Conference November 2-4 2010, Kuching, Malaysia Metropolitan area –1.1 million people –6 water supply systems Country area –0.4 million people –74 Potable Drinking Water Supply Systems and 17 Non-Potable Systems
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The question of monitoring Why bother? Water Safety Conference November 2-4 2010, Kuching, Malaysia
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1.CONTEXT (Cont) ADWG The Australian Drinking Water Guidelines, (ADWG, 2004) provides guidance on the development of monitoring programs Fact Sheets A-Z Framework for Drinking Water Quality Management High level and generic guidance, based on typical water types Guidance designed for larger systems Water Safety Conference November 2-4 2010, Kuching, Malaysia
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2. TYPES OF MONITORING Defined 1.Verification monitoring/ base program 2.Operational Monitoring 3.Event based monitoring Water Safety Conference November 2-4 2010, Kuching, Malaysia
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2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider Water Safety Conference November 2-4 2010, Kuching, Malaysia 1.Verification monitoring /base program: generally at customer taps and with consideration of population size Include requirements from regulators or Dept of Health Include annual reporting requirements and objectives Consider utility’s key performance indicators (KPIs) Consider long-term monitoring (historical trends) of parameters required for asset management, reviewing catchment management initiatives, monitoring drought, seasonal variation, research 2.Operational Monitoring 3.Event Based Monitoring
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2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider Water Safety Conference November 2-4 2010, Kuching, Malaysia 1.Verification monitoring /base program 2.Operational monitoring : residual and water age management, water treatment plant operation Key Performance Indicators (KPIs) 3.Event Based Monitoring
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2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider Water Safety Conference November 2-4 2010, Kuching, Malaysia 1.Verification monitoring /base program 2.Operational monitoring 3.Event Based Monitoring Targeted monitoring for a hazard when barriers are under challenge -> protocols Useful for parameters which are primarily rain or event derived -> protocols Targeted monitoring when “change” is noted –> alarm bells should sound
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2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider 3. Event Based Monitoring (cont) : 3 examples Water Safety Conference November 2-4 2010, Kuching, Malaysia Cryptosporidium / Giardia – often washed in from catchment during rain events – little useful data is gathered by a set (routine) frequency Pesticides – often washed in from catchments during rain events – need to evaluate pesticides used in catchment Bore Integrity – use turbidity, nitrates and micro to determine whether bores subject to surface water intrusion during rain events
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2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider Water Safety Conference November 2-4 2010, Kuching, Malaysia More on....2. Operational monitoring (Continued): 1.Data quality is a major factor - can you trust the data and can you adequate manage the risk with the data? Data integrity (calibration, AQCs) Timeliness – (time delays with operational monitoring e.g. if chlorine analyser samples every 2, 5 or fifteen minutes and communication delays impacts how quickly you can respond to an incident and shut down system) 2.Combination of parameters may prove useful (e.g. if pH increases and free ammonia decreases then indicates nitrification)
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2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider Water Safety Conference November 2-4 2010, Kuching, Malaysia 2. Operational monitoring (Continued): 3.Level of alarms if you set too high then may be too late to react, too low then “noise” may trigger alarm ideally monitor trends of parameters (outlier report) 4.CCP's monitored to manage risk in a system 5.Operational monitoring should be managed with caution: Automation can lead to over reliance on number s Operational knowledge could deteriorate (understand sampling times, error margins, alarms, reporting mechanisms)
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3. RISK BASED APPROACH TO MONITORING Water Safety Conference November 2-4 2010, Kuching, Malaysia Caution should be taken in designing and relying on monitoring: Avoid over-reliance on numerical values Adopt multiple barrier approach to ensure safe drinking water Design monitoring program with the risk to be managed in mind Risk of pathogens in water (acute)- >chlorine residual-> Online (continuous monitoring) Risk of low level chemicals in water (chronic)-> regular but less frequent monitoring
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3. RISK BASED APPROACH TO MONITORING (Cont) Water Safety Conference November 2-4 2010, Kuching, Malaysia SA Water has adopted the following process: 1.Establish a baseline monitoring program based on barriers across each system. This involves categorising each barrier and incorporating research, infrastructure and operational monitoring requirements 2.Based on systematic risk assessment, increase the monitoring and frequency of certain parameters to monitor that risk, including event-based monitoring 3.Continuously review historical information and refine monitoring program
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3. RISK BASED APPROACH TO MONITORING (Cont) Assessing Risk Water Safety Conference November 2-4 2010, Kuching, Malaysia Risk LevelRiskADWG VERY HIGH Significant hazard is present in significant levels in source – system may have none or only a single barrier to control Hazard above health criteria HIGH Significant hazard is present and not well controlled by system Hazard near or just above health criteria MEDIUM Hazard is present, but not at high levels and system can control with multiple barriers Hazard below health criteria but above aesthetic criteria LOWHazard may be present but easily controlled Hazard well below any aesthetic criteria
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3. RISK BASED APPROACH TO MONITORING (Cont) Classify sources and barriers Water Safety Conference November 2-4 2010, Kuching, Malaysia Identify: Minimum monitoring requirements for each source, considering the barriers and the parameters at risk Those parameters only required to be monitored on an event- basis for each sub-barrier
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3. RISK BASED APPROACH TO MONITORING (Cont) Classify sources and barriers Water Safety Conference November 2-4 2010, Kuching, Malaysia Example: Classify type of Bores One of twenty in a field accessing the same aquifer and mixing all water in a tank prior to chlorination Primary bore – sole source of supply for a system Secondary bore which supplies only during peak demand Emergency bore which only supplies water if all other primary sources (bore or surface water) fail Newly drilled bore in a confined aquifer
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3. RISK BASED APPROACH TO MONITORING (Cont) Considerations Water Safety Conference November 2-4 2010, Kuching, Malaysia Locating sample points so they are representative – –customer taps should be located at a range of different locations (dead ends, areas with loops and so on) Regular review of customer tap locations to ensure major population centres covered (expansions) Sufficient numbers of sample points to ensure capture hazards appropriately (population centres, number of locations across a lake or river and so on) Increase monitoring at areas where there are unknowns
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3. RISK BASED APPROACH TO MONITORING (Cont) Surrogates and staged monitoring Water Safety Conference November 2-4 2010, Kuching, Malaysia THMs as a disinfection by-product (DBP) surrogate –If high levels then scan for other DBP’s Algae base program; escalation to other parameters Hot and cold odours to capture taste and odours issues –algal blooms, health of distribution systems, growths in storages, hydrocarbon contamination of groundwater Turbidity or suspended solids to measure changes in source water quality –bore integrity, reverse flow in distribution systems
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3. RISK BASED APPROACH TO MONITORING (Cont) Monitoring frequency of parameters based on risk - examples Water Safety Conference November 2-4 2010, Kuching, Malaysia Cryptosporidium / Giardia Amoeba (such as Naegleria fowleri) Pesticides Organic chemicals Disinfection by-products
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3. RISK BASED APPROACH TO MONITORING (Cont) Historical Trending Water Safety Conference November 2-4 2010, Kuching, Malaysia Historical trending identifies: Changes over time Allows comparison of seasonal changes Measure impacts of catchment management practices, new infrastructure, changing operation Drought impacts Allows you to identify trends of parameters and whether the risk is increasing or decreasing with time
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3. RISK BASED APPROACH TO MONITORING (Cont) Case Studies Water Safety Conference November 2-4 2010, Kuching, Malaysia Case Study #1 –Two bores supplying a tank, treated by UV at the tank outlet and supplying two towns, one of 5,000 people and the other 2,000 Case Study #2 - A river supplying a town of 20,000 people Case Study #3 – A small isolated bore system to a tank feeding a population of 100 people
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Case Study # 1 Two bores supplying a tank, treated by UV at the tank outlet and supplying towns of 5,000 people. Water Safety Conference November 2-4 2010, Kuching, Malaysia A full set of chemistry: bore 2 has high Cd above ADWG Monitoring bores: monthly baseline micro + TDS Tank outlet: Cd when bore 2 online (summer) UV unit - UV transmissivity Tank – regular micro prior and post Customer taps: – depend on configuration of the networks; need to capture major population centres and any high risk areas (industrial, hospital, many private bore schemes, bore pipework integrity, collections of dead-ends).
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Case Study # 2 A river supplying a town of 20,000 people. The water off-take is downstream of stormwater outfall. Water Safety Conference November 2-4 2010, Kuching, Malaysia Event-based sampling + pesticides Survey of river – Al, Fe, Mn above aesthetic levels – monitor distribution system Algal blooms - several locations upstream The town will need a number of customer taps depending on the shape of the town to capture major population centres, and capture range of locations (dead-ends, loops).
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Case Study # 3 A small isolated bore system feeding to a tank; historical ADWG compliance; a population of 100 people Water Safety Conference November 2-4 2010, Kuching, Malaysia Base program for a primary bore put in place with most chemistry once a year, and Regular salinity and micro If any levels of ADWG elevated then frequency is increased accordingly. Simple survey of catchment ; pesticide use and some livestock - event-based program put in place to monitor for pesticides during peak month of use; after heavy rain community person calls local utility operator and samples are taken for turbidity, nitrates, micro
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Summary Water Safety Conference November 2-4 2010, Kuching, Malaysia Ensure adequate verification/ base program is in place to compliment online monitoring and increase confidence in how barriers perform under varying conditions Understand your system, explore the unknowns and monitor to address gaps Use event-based monitoring to assess and manage the risk of key parameters at the optimum time Cost effective monitoring programs should adequately monitor risks and must not substitute a multiple barrier approach
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Acknowledgement Dr Jeremy Lucas South Australian Water Corporation Water Safety Conference November 2-4 2010, Kuching, Malaysia
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