Across Australia, most water and wastewater treatment plants are already well designed. They have robust treatment trains, capable operators, and decades of operational knowledge embedded in their teams.
Yet many plants still underperform where it matters most: filter run length, headloss stability, breakthrough risk, backwash efficiency, odour control reliability, and whole of life cost. The reason may lie in plain sight and it is rarely the process.
More often, it is the way filtration media and activated carbon are specified, procured, and supported. Utilities don’t fail because they picked the “wrong” media. They fail because they bought media and thought the work ended there. What they needed was an outcome from this media.
Media is not the asset. Performance is
In too many projects, filtration media is treated as a consumable line item. Some of the giveaway clauses that appear regularly in procurement documents such as “like for like replacement”, “meets the standard” or “equivalent grade” tell us almost nothing about whether a filter will actually run longer, backwash less, remove more, or operate more safely.
Two media products can technically comply with the same headline standard and once installed, still deliver very different operational outcomes.
Utility magazine has already explored how pore structure, geometry and chemistry influence performance in both water and wastewater applications; the same principle applies just as strongly to grading control, durability and consistency.
The outcome is not “anthracite” or “activated carbon”. The outcome water utilities can be summed up in six priorities:
- Longer filter runs
- Predictable headloss development
- Stable effluent quality
- Fewer emergency change outs
- Lower water and energy consumption
- Safer, simpler maintenance
Media is simply the tool to meet these objectives.
What utilities may specify – and where it falls short
Most Australian water utilities rely on a familiar set of benchmark parameters when specifying filter media or activated carbon:
- For Australian Filter Coal (Anthracite- type filter media)
- Effective Size (ES)
- Uniformity Coefficient (UC)
- Apparent density or specific gravity
- Acid solubility
- Standards compliance (e.g. AWWA B100 type criteria)
- For activated carbon
- Iodine number
- Particle size distribution
- Bulk density
- Hardness / attrition resistance
- Drinking water compliance certifications
These parameters are important — but they are not outcomes.
- They are inputs, and on their own they do not tell you:
- How quickly headloss will rise
- How evenly solids will penetrate the bed
- How tolerant the media will be to hydraulic or water quality swings
- How consistently future deliveries will perform
- How much absorption or length of the media will last given the contaminant parameters
- How safe and practical the media will be to handle and maintain
In not analysing these outcomes, many utilities unknowingly accept performance risk.
The real performance gap: consistency, not capability
Image: Samuel/stock.adobe.com
In theory, most media works.
In practice, small deviations compound over time:
- Slightly wider grading → faster headloss → shorter runs
- Higher fines content → more frequent backwashing → higher OPEX
- Inconsistent carbon density → unpredictable breakthrough → early replacement
- Inconsistent settling of “floaters” → longer and more difficult commissioning times
- Poor handling characteristics → safety and confined space risks
These issues rarely show up in datasheets. They show up six to twelve months later, when operators are forced to intervene more often than expected, or worse when the media is procured.
Buying outcomes means changing the question
Taking a different approach, utilities can . Instead of asking “Does this media meet the spec?” high-performing utilities are asking more detailed questions (see below) about target filter run time and the acceptable headloss profile. They are also investigating the predictability of breakthrough behaviours and the level of operator intervention. Once those questions are clear, media selection becomes a technical optimisation exercise, not a purchasing exercise.
Five vital questions for utilities for better outcomes
- What filter run time are we trying to achieve?
- What headloss profile is acceptable for hydraulics?
- How predictable do we need breakthrough behaviour to be?
- How much operator intervention are we prepared to accept?
- What is the cost per year of performance, not cost per tonne delivered?
The right partner makes the difference
This is where the role of a supplier ends — and the role of a technical partner begins. James Cumming works with utilities on the assumption that most plants can be optimised further, without major capital works.
The lever is not changing the process, but aligning media grading and geometry, carbon structure and density. Ensuring handling, loading and safety practices also fit into this process, along with monitoring and change out strategies
Because James Cumming manufactures filtration media and activated carbon locally, technical support does not stop at supply.
Their support extends into translating plant objectives into media specifications that reflect outcomes, not just standards. They also support utilities in understanding why two “compliant” products behave differently in service.
James Cumming does this by working alongside operators and engineers to interpret performance trends and adjust media strategy accordingly. They also provide continuity of supply and performance, rather than variability from shipment to shipment
In January, Utility magazine demonstrated the value of this approach in the context of odour control, recycled water and carbon selection. The same thinking needs to apply to every filter bed and carbon contactor.
Optimisation; not a project but a relationship
The most reliable water and wastewater assets in Australia share a common trait: they are supported by partners who understand how the plant behaves, not just how it was designed.
Optimising filtration media and activated carbon is rarely about changing everything.
It is about making fewer, better informed decisions, supported by local technical expertise and manufacturing control.
When utilities stop buying media — and start buying outcomes — filter beds last longer, carbon works harder, operators intervene less, and risk reduces quietly in the background.
That is not a product story. It is a story about operational relationships.
For more information, visit jamescumming.com.au
This article appears in the March/April 2026 edition of Utility. Subscribe HERE.
