Chlorine vs Chloramine in SA Tap Water: What It Does to Your Plumbing
23 July 2026 · Plumbers On Duty
Chlorine vs Chloramine in SA Tap Water: What It Does to Your Plumbing
SA municipalities disinfect drinking water two ways. Knowing which one you're on tells you which fittings will fail first.
Who uses what
| Metro | Disinfectant | Typical residual |
|---|---|---|
| Joburg, Ekurhuleni, Tshwane (Rand Water) | Chloramine | 1.0 to 2.5 mg/L |
| Cape Town | Free chlorine | 0.5 to 1.2 mg/L |
| eThekwini (Umgeni) | Chloramine + chlorine boost | 1.5 to 3.0 mg/L |
| Nelson Mandela Bay | Free chlorine | 0.3 to 0.8 mg/L |
| Most Karoo towns | Free chlorine (higher dose) | 1.5 to 3.5 mg/L |
What each attacks
Free chlorine , aggressive on rubber. O-rings, tap washers, flexi-hose linings, dishwasher door seals. Replace washers every 3 to 5 years in Cape Town.
Chloramine , aggressive on brass and copper (see our copper pinhole pitting guide). Also destroys natural rubber, so use EPDM-lined flexis, not standard rubber, in Rand Water areas.
Filter choices
| Filter type | Removes chlorine? | Removes chloramine? |
|---|---|---|
| Standard carbon | Yes | Partially |
| Catalytic carbon | Yes | Yes |
| Reverse osmosis | Yes | Yes |
| KDF-55 | Yes | Partially |
Rand Water customers should specify catalytic carbon filters, not standard. Brands: Aquacooler, Ozone, H2O International. Available at Builders, Leroy Merlin, and specialist water shops.
Practical takeaways
- Joburg / Pretoria , spec brass fittings with dezincification-resistant (DZR / CR) marking
- Cape Town , stock spare tap washers, replace flexi-hoses every 5 years
- Both , if hot water smells of TCP/hospital, chloramine + trace organics is the cause, flush the geyser
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