annelie lourens dr jeremy lucas south australian water corporation improving system performance...
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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
Improving System Performance through the process of operational monitoring
Context of Experience:
Water Safety ConferenceNovember 2-4 2010, Kuching, Malaysia
Improving System Performance through the process of operational monitoring
Context of Experience:
• South Australia
Water Safety ConferenceNovember 2-4 2010, Kuching, Malaysia
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
1. CONTEXT:
Water supplied by South Australian Water Corporation
Water Safety ConferenceNovember 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
1. CONTEXT (Cont)
South Australian Water Monitoring Program
Water Safety ConferenceNovember 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
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 ConferenceNovember 2-4 2010, Kuching, Malaysia
2. TYPES OF MONITORING
Defined
1. Verification monitoring/ base program
2. Operational Monitoring
3. Event based monitoring
Water Safety ConferenceNovember 2-4 2010, Kuching, Malaysia
2. TYPES OF MONITORING (Cont)
Building the Monitoring Program – Factors to consider
Water Safety ConferenceNovember 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
2. TYPES OF MONITORING (Cont)
Building the Monitoring Program – Factors to consider
Water Safety ConferenceNovember 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
2. TYPES OF MONITORING (Cont)
Building the Monitoring Program – Factors to consider
Water Safety ConferenceNovember 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
2. TYPES OF MONITORING (Cont)
Building the Monitoring Program – Factors to consider
3. Event Based Monitoring (cont) : 3 examples
Water Safety ConferenceNovember 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
2. TYPES OF MONITORING (Cont)
Building the Monitoring Program – Factors to consider
Water Safety ConferenceNovember 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)
2. TYPES OF MONITORING (Cont)
Building the Monitoring Program – Factors to consider
Water Safety ConferenceNovember 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)
3. RISK BASED APPROACH TO MONITORING
Water Safety ConferenceNovember 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
3. RISK BASED APPROACH TO MONITORING (Cont)
Water Safety ConferenceNovember 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
3. RISK BASED APPROACH TO MONITORING (Cont)
Assessing Risk
Water Safety ConferenceNovember 2-4 2010, Kuching, Malaysia
Risk Level Risk ADWG
VERY HIGHSignificant hazard is present in significant levels in source – system may have none or only a single barrier to control
Hazard above health criteria
HIGHSignificant hazard is present and not well controlled by system
Hazard near or just above health criteria
MEDIUMHazard is present, but not at high levels and system can control with multiple barriers
Hazard below health criteria but above aesthetic criteria
LOW Hazard may be present but easily controlledHazard well below any aesthetic criteria
3. RISK BASED APPROACH TO MONITORING (Cont)
Classify sources and barriers
Water Safety ConferenceNovember 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
3. RISK BASED APPROACH TO MONITORING (Cont)
Classify sources and barriers
Water Safety ConferenceNovember 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
3. RISK BASED APPROACH TO MONITORING (Cont)
Considerations
Water Safety ConferenceNovember 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
3. RISK BASED APPROACH TO MONITORING (Cont)
Surrogates and staged monitoring
Water Safety ConferenceNovember 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
3. RISK BASED APPROACH TO MONITORING (Cont)
Monitoring frequency of parameters based on risk - examples
Water Safety ConferenceNovember 2-4 2010, Kuching, Malaysia
•Cryptosporidium / Giardia•Amoeba (such as Naegleria fowleri)•Pesticides•Organic chemicals•Disinfection by-products
3. RISK BASED APPROACH TO MONITORING (Cont)
Historical Trending
Water Safety ConferenceNovember 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
3. RISK BASED APPROACH TO MONITORING (Cont)
Case Studies
Water Safety ConferenceNovember 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
Case Study # 1
Two bores supplying a tank, treated by UV at the tank outlet and supplying towns of 5,000 people.
Water Safety ConferenceNovember 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).
Case Study # 2
A river supplying a town of 20,000 people. The water off-take is downstream of stormwater outfall.
Water Safety ConferenceNovember 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).
Case Study # 3
A small isolated bore system feeding to a tank; historical ADWG compliance; a population of 100 people
Water Safety ConferenceNovember 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
Summary
Water Safety ConferenceNovember 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
Acknowledgement
Dr Jeremy Lucas
South Australian Water Corporation
Water Safety ConferenceNovember 2-4 2010, Kuching, Malaysia
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