💧 In simple terms: Pick your city below and we'll show you what's in your tap water, whether it's good for coffee, and exactly what to do about it. Every profile now has an SCA Delta score (0–100, higher = closer to ideal) and a brew verdict. Scroll down for the national ranking and Cape Town treatment plant breakdown.
🗺️ The Big Picture — SA's water personality zones
Moderate minerals, balanced alkalinity. Closest to the SCA ideal in SA. Joburg, Pretoria, Midvaal — just filter for chlorine and brew.
Slightly softer, decent mineral content. Filter chlorine, then brew. Durban, Pietermaritzburg, Bloemfontein — solid B-tier water.
Very soft, low mineral, mountain-catchment water. Needs remineralisation for coffee. Cape Town, Stellenbosch, Gqeberha — add minerals or go bottled.
🏆 National Tap Water Ranking for Coffee
| # | City / Zone | SCA Δ | Verdict | Machine? |
|---|---|---|---|---|
| 🥇 | Johannesburg (Vaal) | 70 | Brew straight from tap | ✅ |
| 🥈 | Pretoria (Vaal) | 70 | Brew straight, filter for pipes | ✅ |
| 🥉 | Durban (Umgeni) | 65 | Off-gas chlorine, then brew | ✅ |
| 4 | Bloemfontein | 55 | Chlorine-filter first | ✅ |
| 5 | CT (Helderberg/Witzands) | 50 | Best of CT for filter | ✅ |
| 6 | CT (Voëlvlei/Faure) | 45 | Filter only, needs minerals | ✅ |
| 7 | Stellenbosch / Hermanus | 40 | Add minerals or use bottled | ✅ |
| 8 | CT (Steenbras/Kloof Nek) | 35 | Too soft, pH too high | ✅ |
| 9 | CT (Wemmershoek) | 30 | Don't brew with it | ✅ |
| 10 | Gqeberha | 25 | Use bottled for brewing | ❌ |
| 11 | Kimberley | n/a | Use bottled or refill stations | ❌ |
SCA Δ = closeness to SCA ideal (0–100). Machine? = safe for espresso machine without descaling every month. n/a = no data to score.
SA municipalities publish per supply zone, not per street.
Got a cheap TDS pen? Enter it to override the city default.
Johannesburg
All Joburg suburbs — Sandton, Rosebank, Soweto, Randburg, Roodepoort, Midrand, etc.
What I'd do
Lucky you. Just brew with tap. Maybe a carbon filter to remove chlorine taste, but the minerals are pretty much what the SCA ordered.
About the fallback estimate(s)
Alkalinity is NOT published by Rand Water. Shown as a fallback ≈ total hardness (bicarbonate-dominated SA water; Umgeni Water research shows alkalinity:hardness ≈ 0.9–1.1). Treat as an estimate, not a measurement.
What I'd try
- A carbon + ion-exchange jug filter (e.g. BWT/Brita-style) softens hardness and trims alkalinity towards the SCA box.
- Try Valpré — it's the closest mainstream SA bottled water to SCA spec.
Every figure links to its source and report date. Where a municipality or brand doesn't publish a value, this tool shows “not published” rather than estimating. We believe missing data honestly disclosed is more useful than a confident guess. Where we tested ourselves (Gauteng reagent tests), the method and date are documented.