Chloramine
A longer-lasting disinfectant formed by combining chlorine with ammonia, used in some Australian water supplies.
ADWG Guideline
3 mg/L
Chloramine (monochloramine) is an alternative to free chlorine for water disinfection. It is formed by adding ammonia to chlorinated water and provides a longer-lasting disinfectant residual.
Why it matters
The ADWG sets a guideline of 3 mg/L for monochloramine.
- Longer lasting: Chloramine persists further through the pipe network than free chlorine, making it useful for large distribution systems
- Fewer byproducts: Produces lower levels of trihalomethanes (THMs) than free chlorine
- Less taste and odour than chlorine at equivalent disinfection levels
Where it’s used in Australia
Major utilities using chloramine include parts of Melbourne (Melbourne Water), South East Queensland (Seqwater), and some Sydney Water supply zones. Many utilities switch between chlorine and chloramine seasonally.
Important for aquarium owners
Chloramine is toxic to fish and cannot be removed by simply letting water stand, unlike free chlorine. Aquarium owners in chloraminated areas must use a dedicated water conditioner.
Related Terms
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Disclaimer: Glossary definitions are provided for general educational purposes only and do not constitute medical advice or professional guidance. For specific health concerns about your drinking water, consult a qualified health professional. See our Terms of Use.