Chloramine in Australian Tap Water: Why Your Standard Filter Is Not Enough

What Is Chloramine and Why Is It in Your Water?

Most Australians assume their tap water is disinfected with chlorine. For many city households, that assumption has not been accurate for years. Australia's major water utilities have progressively moved from free chlorine to chloramine as their primary disinfectant, and the difference matters significantly if you are relying on a standard carbon filter.

Chloramine is formed by combining chlorine with ammonia. Water authorities prefer it because it is more stable over the long distribution distances that characterise Australian water networks. Free chlorine dissipates as it travels through kilometres of pipes, which can result in under-disinfected water at the far end of the system. Chloramine holds its disinfecting residual more consistently from the treatment plant to the tap.

Utilities also choose chloramine because it generates lower concentrations of trihalomethanes (THMs), a family of disinfection by-products that form when free chlorine reacts with organic matter in water. Chloramine produces a different set of by-products instead, and the overall profile of both remains within the limits set by the Australian Drinking Water Guidelines.

Which Australian Cities Use Chloramine?

The list includes Sydney Water, Melbourne Water across the majority of the reticulated supply, Urban Utilities in Brisbane and surrounding areas, SA Water in Adelaide, Icon Water in Canberra, and Perth's Water Corporation in parts of its network.

This covers the majority of the Australian population. If you live in any of these cities and your current filter is a standard activated carbon jug or a basic tap diverter system, the filter is likely providing very little removal of the primary disinfectant in your water. This is not a failure of the filter itself. It is simply that the filter was not designed for chloramine.

To confirm what disinfectant your local utility uses, check their annual water quality report. Every major utility publishes one. The disinfection section will specify whether free chlorine or chloramine, sometimes listed as monochloramine or combined chlorine, is used and at what residual concentrations it is maintained throughout the distribution network.

Why Standard Carbon Filters Do Not Remove Chloramine Effectively

Standard granular activated carbon (GAC) is highly effective at removing free chlorine. It works through a surface reaction at the carbon media, breaking down chlorine molecules rapidly and reliably. This is why standard carbon filter jugs and basic under-sink carbon systems consistently improve the taste and smell of chlorinated water.

Chloramine does not respond to the same mechanism. The bond between chlorine and ammonia in chloramine is more stable than free chlorine alone, and standard GAC removes it at a fraction of the efficiency. Under real-world conditions, standard GAC filters typically remove less than 10 per cent of chloramine at normal residential flow rates.

The practical result: a household in Sydney or Brisbane running water through a standard jug filter may find their filtered water tastes no different from unfiltered. The filter is performing exactly as intended for chlorine. It is simply the wrong technology for the water it is being asked to treat.

Standard Brita Classic and Plus filters, for example, are certified to NSF/ANSI Standard 42 for chlorine taste and odour reduction. They carry no certification for chloramine removal. The same is true of most entry-level filter products marketed on price rather than specification.

How to Tell If Your Filter Is Rated for Chloramine

The most reliable way to check is to look at the filter's independent certification. NSF/ANSI Standard 42 covers chlorine taste and odour. NSF/ANSI Standard 53 covers health-effect reductions including certain contaminants. Neither standard requires chloramine removal for certification.

A filter specifically rated for chloramine removal will state it in the product's certified performance data or third-party test results. If the documentation only references chlorine, it has not been tested or certified for chloramine. Do not assume coverage based on general marketing language about water quality improvement.

What Actually Removes Chloramine

Two technologies are reliably effective: catalytic activated carbon and reverse osmosis.

Catalytic Activated Carbon

Catalytic activated carbon is engineered with higher surface reactivity than standard GAC. Rather than the simple adsorption mechanism that works for chlorine, catalytic carbon breaks the chloramine molecule through a different chemical pathway. The result is substantially better chloramine removal than any standard activated carbon media.

Under-sink systems using catalytic carbon block media are a practical option for households in chloramine cities that want effective disinfectant removal and improved taste without the footprint of a full reverse osmosis system. The key is confirming the filter specification before purchasing, not just relying on general water quality claims.

Reverse Osmosis

A reverse osmosis system removes chloramine at the membrane stage through physical rejection. The semi-permeable RO membrane blocks dissolved compounds, and the carbon pre-filter in a complete multi-stage setup handles a further proportion of the chloramine load before the water reaches the membrane. The combined result is effective chloramine removal alongside a broad range of other contaminants.

Beyond chloramine, a reverse osmosis system addresses fluoride, PFAS, nitrates, heavy metals, and microplastics in a single under-sink installation. For households in chloramine cities that also have concerns about any of these other contaminants, RO provides the most comprehensive residential coverage available. For a detailed comparison of how carbon and RO systems perform across the full contaminant picture, see our guide to carbon filtration versus reverse osmosis.

Is Chloramine Harmful?

Chloramine in town water at regulated concentrations is considered safe to drink by Australian health authorities. The Australian Drinking Water Guidelines set health-based guidance values for chloramine residuals, and utilities test throughout the distribution network to confirm compliance. The Australian Government's Department of Health provides further information on water quality standards and how they are maintained.

Some research has examined whether chloramine exposure through shower steam may affect people with respiratory sensitivities, since chloramine does not off-gas as readily as free chlorine. This is an active area of research rather than a settled health position, and it relates primarily to inhalation exposure rather than drinking water.

For dialysis patients, chloramine is a specific medical concern. Water used in haemodialysis contacts the bloodstream directly and must be completely free of chloramine. This is managed at a clinical facility level and is separate from general household drinking water use.

For most households, the primary practical concern is not that chloramine at regulated levels causes acute harm. It is that relying on a filter not rated for chloramine while assuming it is doing the job is an invisible gap in your water quality setup.

Chloramine and Shower Filters

If you are considering a shower filter in a chloramine city, the filter media matters significantly. Most standard shower filters marketed for chlorine removal perform poorly against chloramine for exactly the reasons described above. Effective chloramine reduction in a shower requires either catalytic carbon or KDF (Kinetic Degradation Fluxion) media, which uses an electrochemical process to break chloramine down at higher temperatures and flow rates.

For drinking water, point-of-use filtration at the kitchen tap remains the most practical and controllable approach. The lower temperature and longer contact time in a kitchen filter allow catalytic carbon and RO membranes to work most efficiently. Shower filtration is a secondary consideration, and the media must be matched specifically to the disinfectant in your supply.

Chloramine and Household Fish or Aquariums

Standard aquarium dechlorinator products neutralise free chlorine but are not effective against chloramine. Fish are sensitive to both at the concentrations present in tap water, and using a standard dechlorinator in a chloraminated supply can leave fish exposed. If you keep aquatic animals, check your water supply and use a dechlorinator specifically formulated for chloramine, or use reverse osmosis water as a chloramine-free base for aquarium fills.

What to Do Now

If you are in a chloramine-treated area and have been relying on a standard carbon filter, two steps are worth taking. First, check your utility's annual water quality report to confirm the disinfectant type and residual concentrations in your distribution zone. Second, compare your current filter's certified performance claims against what is actually in your water.

The Purest Solutions filtered tap system uses a high-specification carbon block that significantly outperforms standard GAC across a range of contaminants. For the most comprehensive coverage, including chloramine, fluoride, PFAS, heavy metals, and microplastics, a reverse osmosis system addresses all of them in a single under-sink installation. If PFAS is also a concern in your area, our post on PFAS in Australian drinking water covers that contaminant in detail.

If you are not sure which system suits your local water and household, contact the Purest Solutions team. We can confirm what is in your supply and recommend the right solution.

Summary

Most major Australian cities, including Sydney, Melbourne, Brisbane, and Adelaide, use chloramine rather than free chlorine as their primary water disinfectant. Standard activated carbon filters, including most jug filters, are poorly suited to chloramine removal. Catalytic carbon and reverse osmosis are the effective technologies. If you are relying on a basic carbon filter in a chloramine city, your water may be receiving far less filtration than you expect. Check your utility's water quality report, confirm your filter's specifications, and match the technology to what is actually in your water.