The Water Dictionary

Tap Water in NN9

WellingboroughAnglian Water

Tap water in Wellingborough, supplied by Anglian 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 235 mg/L as CaCO₃.


Mineral composition

mg/L
Calcium80
Magnesium8
Sodium31
Sulfate103
Chloride51
Bicarbonate~150
~ Estimated from hardness and ion balance — not directly measured by the water company.

Additional info

Hardness234.54 as CaCO₃
Alkalinity123.2 as CaCO₃
pH7.45
Conductivity546 µS/cm
SourceAnglian Water
Data year2025

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

Extremely high buffering that makes this water difficult to work with for any brewing or coffee application without significant dilution or acid treatment: mash pH will sit stubbornly high, extraction will be unbalanced, and espresso will taste flat and chalky with no discernible acidity.


Closest water profiles


Nearby areas


Data sourced from Anglian Water (2025). Looking for a specific address? Look up your full postcode for the most accurate result.