The Water Dictionary

Tap Water in SW6

FulhamThames Water

Tap water in Fulham, supplied by Thames Water, has the character of a chalk aquifer source, typical of southern and eastern England. It's moderately hard, in the upper half of the national range, with a total hardness of 254 mg/L as CaCO₃. Bicarbonate is high at 253 mg/L: this water suits dark-roasted, milk-based coffee well, but will strip the acidity from lighter roasts and pour-over brewing.


Mineral composition

mg/L
Calcium95
Magnesium4
Sodium25
Sulfate42
Chloride35
Bicarbonate253

Additional info

Hardness254 as CaCO₃
Alkalinity207 as CaCO₃
pH7.8
Conductivity538 µS/cm
SourceThames Water
Data year2024

What this means

Kettle & appliances

Limescale buildup is noticeable and ongoing. Kettles will develop visible deposits within weeks, and heating elements in boilers and washing machines will need periodic attention. A water softener or scale inhibitor is worth considering.

Espresso

This water will scale espresso machines meaningfully. Flavour-wise, the high mineral content tends to flatten acidity and produce a heavier, less nuanced shot with lighter roasts. Darker roasts and milk-based drinks fare better: the body and density that hard water produces can carry well through milk. Regular descaling is essential, and filtration or blending with softer water is worth considering.

Filter & pour-over

The effect is more noticeable here than in espresso, because the higher water-to-coffee ratio amplifies the mineral influence. Lighter roasts will taste muted and uniform; origin character gets buried. Darker roasts hold up better, but the cup will lack the clarity that filter brewing is best at producing.

Drinking & cooking

The mineral taste is perceptible. Some people prefer it; others find it chalky. Hard water can affect how well soap and detergent lather, and it leaves visible residue on glass and stainless steel.

Bicarbonate

Heavily buffered water that resists pH change substantially: suited only to the darkest, most roast-forward beer styles (and even then may need dilution), while espresso at this level will taste dull, chalky, and lacking definition, with almost all origin character neutralised by the alkalinity.


Closest water profiles


Nearby areas


Data sourced from Thames Water (2024). Looking for a specific address? Look up your full postcode for the most accurate result.