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Water Safety Conference 2010. Annelie Lourens Dr Jeremy Lucas South Australian Water Corporation. Improving System Performance through the process of operational monitoring. Improving System Performance through the process of operational monitoring. Context of Experience:.
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Water Safety Conference 2010 Annelie Lourens Dr Jeremy Lucas South Australian Water Corporation Improving System Performance through the process of operational monitoring
Improving System Performance through the process of operational monitoring • Context of Experience: Water Safety Conference November 2-4 2010, Kuching, Malaysia
Improving System Performance through the process of operational monitoring • Context of Experience: • South Australia Water Safety Conference November 2-4 2010, Kuching, Malaysia
Improving System Performance through the process of operational monitoring • Context of Experience: • South Australia • Australian Drinking Water Guidelines (ADWG) • ADWG Framework • Types of monitoring • Risk based approach to monitoring Water Safety Conference November 2-4 2010, Kuching, Malaysia
CONTEXT: • Water supplied by South Australian Water Corporation • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
CONTEXT (Cont) • South Australian Water Monitoring Program • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
The question of monitoring Why bother? Water Safety Conference November 2-4 2010, Kuching, Malaysia
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
2. TYPES OF MONITORING Defined Verification monitoring/ base program Operational Monitoring Event based monitoring Water Safety Conference November 2-4 2010, Kuching, Malaysia
2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider • 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 • Operational Monitoring • Event Based Monitoring Water Safety Conference November 2-4 2010, Kuching, Malaysia
2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider • Verification monitoring /base program • Operational monitoring : • residual and water age management, • water treatment plant operation • Key Performance Indicators (KPIs) • Event Based Monitoring Water Safety Conference November 2-4 2010, Kuching, Malaysia
2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider • Verification monitoring /base program • Operational monitoring • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider 3. Event Based Monitoring (cont) : 3 examples • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider • More on ....2. Operational monitoring (Continued): • 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) • Combination of parameters may prove useful (e.g. if pH increases and free ammonia decreases then indicates nitrification) Water Safety Conference November 2-4 2010, Kuching, Malaysia
2. TYPES OF MONITORING (Cont) Building the Monitoring Program – Factors to consider • 2. Operational monitoring (Continued): • 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) • CCP's monitored to manage risk in a system • 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) Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) • SA Water has adopted the following process: • Establish a baseline monitoring program based on barriers across each system. This involves categorising each barrier and incorporating research, infrastructure and operational monitoring requirements • Based on systematic risk assessment, increase the monitoring and frequency of certain parameters to monitor that risk, including event-based monitoring • Continuously review historical information and refine monitoring program Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) Assessing Risk Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) Classify sources and barriers • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) Classify sources and barriers • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) Considerations • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) Surrogates and staged monitoring • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) Monitoring frequency of parameters based on risk - examples • Cryptosporidium / Giardia • Amoeba (such as Naegleria fowleri) • Pesticides • Organic chemicals • Disinfection by-products Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) HistoricalTrending • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
3. RISK BASED APPROACH TO MONITORING (Cont) Case Studies • 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 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 towns of 5,000 people. • 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). Water Safety Conference November 2-4 2010, Kuching, Malaysia
Case Study # 2 A river supplying a town of 20,000 people. The water off-take is downstream of stormwater outfall. • 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). Water Safety Conference November 2-4 2010, Kuching, Malaysia
Case Study # 3 A small isolated bore system feeding to a tank; historical ADWG compliance; a population of 100 people • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
Summary • 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 Water Safety Conference November 2-4 2010, Kuching, Malaysia
Acknowledgement Dr Jeremy Lucas South Australian Water Corporation Water Safety Conference November 2-4 2010, Kuching, Malaysia