Table of Contents
Executive Summary
The most useful lesson from the 2026 AWA/IWA Young Water Professionals Conference in Melbourne was not about any single treatment technology. It was about systems thinking. Four research projects — manganese discolouration, THM reduction, PFAS destruction and nitrification control — each showed that fixing one drinking water problem can create another.
Greater Western Water found that polyphosphate sequestration for manganese adds phosphate load to wastewater. Logan Water found that reservoir aeration for THM removal lifts pH, which changes chlorine chemistry. University of Queensland found that electrochemical PFAS destruction has to be validated through fluoride tracking, not just a falling PFAS concentration. Sydney Water found that disinfectant switching for nitrification control needs continuous monitoring to prevent unexpected residual loss.
The common thread: multi-parameter inline monitoring is what separates a controlled, understood intervention from an unintended consequence. Shanghai ChiMay’s range of inline water quality analyzers — pH, conductivity, residual chlorine, turbidity, COD, dissolved oxygen, and the integrated 4-in-1 multi-parameter sensor — provides the simultaneous continuous measurement that systems-level water treatment management requires.
Four Case Studies in Systems Thinking
Case 1: Manganese Sequestration and Phosphate Loading
Greater Western Water’s Samuel Leong tested polyphosphate sequestration to stop manganese discolouration after chlorination. The treatment worked: food-grade polyphosphate kept manganese soluble and prevented discolouration in jar tests and in site trials at the Rosslynne Water Filtration Plant.
The team also checked what else they were changing. Polyphosphate contains phosphate, and adding it to drinking water increases the phosphorus load arriving at wastewater treatment. Their calculations suggested the additional load would be small, but further testing was planned.
The monitoring implication: if sequestration is deployed at scale, continuous monitoring of phosphate — and potentially orthophosphate as polyphosphate hydrolyses — becomes necessary in both drinking water and wastewater effluent. Shanghai ChiMay conductivity meters detect the ionic changes from chemical addition, and the wider multi-parameter platform supports the comprehensive monitoring this intervention needs.
Case 2: Reservoir Aeration and pH Shift
Logan Water’s Cassandra Mai presented six-month reservoir aeration trial results: approximately 83% THM removal at roughly four cents per megalitre. A strong result, with a caveat.
The aeration process stripped CO₂ from the water, raising pH by about 0.3 units beyond the normal change through the reservoir. That shift affects chlorine speciation (less HOCl, more OCl⁻ at higher pH) and has to be managed to hold disinfection effectiveness.
The monitoring implication: running pH and residual chlorine monitoring at the reservoir outlet at the same time confirms that THM reduction is not being paid for with disinfection protection. Shanghai ChiMay’s inline pH meters and residual chlorine transmitters, integrated through Modbus into SCADA, provide that verification in real time.
Case 3: PFAS Electrochemical Treatment and Verification Gaps
University of Queensland’s Andrea Veciana demonstrated more than 80% PFAS removal through electrochemical degradation. An important result — but she cautioned that a falling PFAS concentration proves nothing about destruction:
“Many times, people report ‘I’ve achieved a 99 per cent removal of PFAS,’ but where did that PFAS go?”
Fluoride tracking and a complete fluorine mass balance are required to distinguish genuine molecular destruction from phase transfer.
The monitoring implication: continuous conductivity and COD monitoring gives real-time indicators of ionic and organic carbon change during electrochemical treatment. Correlated against periodic grab-sample PFAS analysis, those continuous parameters build a full picture of whether destruction is actually occurring.
Case 4: Disinfectant Switching and Nitrification Return
Sydney Water’s Madison Mactal and Michael Ray described switching from monochloramine to free chlorine across 14 reservoirs serving approximately 105,000 customers to control nitrification. The first trial in 2024 fell short of their internal 90% disinfection target. The redesigned 2025 trial performed better — but nitrification returned once warmer conditions resumed.
The monitoring implication: continuous residual chlorine monitoring at multiple network points is essential to track the disinfectant transition, confirm breakpoint achievement, detect decay patterns, and pick up the earliest signs of nitrification recurrence.
The Unifying Principle: Multi-Parameter Monitoring Prevents Unintended Consequences
Each case study follows the same shape. The intervention itself was promising, but its secondary effects had to be detected and managed. Not one of those secondary effects would show up through single-parameter monitoring or periodic grab sampling.
The industry is moving toward integrated monitoring architectures where several parameters are measured continuously at the same location — a real-time picture of the system rather than a scatter of isolated data points.
Shanghai ChiMay’s Multi-Parameter Platform
Shanghai ChiMay supports this integrated approach through:
Individual inline instruments:
– In-line pH meters
– In-line conductivity meters
– Residual chlorine transmitters (free or total)
– Online turbidity testers
– COD sensors
– Dissolved oxygen transmitters
– Ammonia nitrogen sensors
– ORP measurement
The 4-in-1 Multi-Parameter Sensor: pH, conductivity, ORP and temperature in a single 180 mm probe body. This integration:
– Reduces installation points by 75%
– Eliminates alignment errors between separate sensor measurements
– Cuts installation cost by approximately 40%
– Provides four synchronized data streams from one penetration point
Digital infrastructure: every Shanghai ChiMay instrument communicates over Modbus RTU/TCP, so data lands in any modern SCADA platform — on operator screens, in historical trend logs, and available for AI/ML analytics.
The Economic Case for Integrated Monitoring
Is multi-parameter inline monitoring worth the money? The answer sits in the cost of not knowing:
- Manganese discolouration complaints trigger field investigations, flushing operations and customer relations costs
- THM exceedances trigger regulatory notifications, treatment adjustments and possible enforcement action
- Nitrification events undermine disinfection protection and can trigger boil-water advisories
- Undetected PFAS concentration rather than destruction creates downstream liability when the concentrated waste stream has to be managed
The cost of the instruments is small next to the cost of the consequences they prevent. Shanghai ChiMay’s 5-year TCO model — including calibration consumables, membrane replacements and technical support — typically comes in 25–35% below multi-vendor discrete sensor approaches.
Buy the sensor, own the outcome. The monitoring investment pays for itself the first time it stops an unintended consequence reaching customers or regulators.
Practical Implementation Framework
For utilities wanting to act on what the conference presentations showed:
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Audit current monitoring gaps: where are treatment decisions being made on single-parameter or grab-sample data? Those are the highest-risk points for unintended consequences.
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Prioritize by intervention risk: if you are implementing sequestration, aeration, electrochemical treatment or disinfectant switching, multi-parameter monitoring at the intervention point is not optional.
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Start with the 4-in-1 sensor: for new monitoring points, the integrated sensor gives four parameters from one installation, maximising data while minimising infrastructure.
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Add dedicated sensors for critical parameters: residual chlorine, turbidity and COD each have dedicated instruments optimised for their specific measurement challenge.
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Integrate into SCADA: Modbus RTU/TCP is immediately compatible. Set alarm thresholds on every parameter so deviations surface before they become problems.
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Build historical datasets: continuous monitoring creates datasets that reveal patterns grab sampling cannot. After 6–12 months, operators can predict seasonal variation and tune intervention timing.
The Systems Thinking Imperative in Modern Water Treatment
Why Single-Parameter Monitoring Is No Longer Sufficient
Historically, treatment processes were designed around one contaminant and one objective. Manganese removal dealt with manganese. THM management dealt with THMs. PFAS treatment dealt with PFAS. Nitrification control dealt with nitrification.
Each conference presentation showed that treatment interventions create cascading effects across the water quality landscape. Change one variable — add polyphosphate, aerate a reservoir, apply electrochemistry, or switch disinfectant — and several parameters move at once. Managing those cascading effects requires simultaneous multi-parameter monitoring that captures the full system response.
The Cost of Not Knowing
Consider what happens when side effects go undetected:
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Undetected manganese precipitation: customer complaints, flushing operations, reputational damage. A single discolouration event — field investigation, customer communication, regulatory notification — can cost more than years of continuous monitoring.
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Unmanaged pH shift during aeration: altered chlorine speciation, which can cut disinfection effectiveness at exactly the moment the utility believes it is improving water quality through THM reduction.
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False confidence in PFAS destruction: if PFAS concentrations fall but the chemicals were merely concentrated rather than destroyed, the concentrated waste stream becomes a liability larger than the original contamination problem.
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Incomplete disinfectant transition: without monitoring, breakpoint chlorination may not be reached at every network point, leaving ammonia in the system that allows rapid nitrification recurrence.
In each case, the cost of the unintended consequence exceeds the cost of preventing it through continuous monitoring.
Building a Multi-Parameter Monitoring Culture
Moving from single-parameter to multi-parameter monitoring is not just a technology decision. It changes how a utility designs, operates and optimises treatment systems.
Design phase: new treatment interventions should include multi-parameter monitoring in the design specification. Procurement documents should state which parameters are to be monitored, the accuracy required, and the data integration architecture.
Operation phase: operators need training to read multi-parameter datasets and recognise the patterns that precede unintended consequences. Alarm thresholds belong on every monitored parameter, not just the primary treatment target.
Optimization phase: historical multi-parameter data enables predictive modelling that anticipates treatment challenges. Seasonal patterns, source water changes and equipment degradation all become visible in continuous data in a way periodic sampling never shows.
Shanghai ChiMay supports that transition with instruments that make multi-parameter monitoring economically and technically reachable. The 4-in-1 multi-parameter sensor in particular lowers the barrier by combining four measurements in one probe body at a fraction of the cost of four discrete sensors.
Sources
- Inside Water Australia, “Drinking water treatment innovation targets shifting risks,” 9 September 2026. https://insidewater.com.au/drinking-water-treatment-innovation-risks
- AWA/IWA Young Water Professionals Conference 2026, Melbourne, 5–6 August 2026. Greater Western Water (Samuel Leong), Logan Water/WSP (Cassandra Mai), University of Queensland (Andrea Veciana) and Sydney Water (Madison Mactal, Michael Ray) presentations.
- Mirzaei, S. & Gorczyca, B., “Removal of trihalomethanes from high organic matter water sources using aeration: a feasibility study,” Water Quality Research Journal, Vol. 55, No. 2, 2020.
- Pure Water Atlas, “Polyphosphate in Drinking Water,” June 2026. https://purewateratlas.com/contaminants/polyphosphate/
About the Author: This article was prepared by the Shanghai ChiMay Application Engineering team, referencing peer-reviewed conference presentations from the 2026 AWA/IWA Young Water Professionals Conference. Shanghai ChiMay manufactures inline water quality analyzers for municipal and industrial water treatment systems worldwide.
