Tap Water in NN5
Northampton West — Anglian Water
Tap water in Northampton West, supplied by Anglian Water, has the character of a blended surface and groundwater supply, with no dominant mineral signature. It’s moderately hard, in the upper half of the national range, with a total hardness of 208 mg/L as CaCO₃.
Mineral composition
| mg/L | |||
|---|---|---|---|
| Calcium | 71 | ||
| Magnesium | 7 | ||
| Sodium | 23 | ||
| Sulfate | 97 | ||
| Chloride | 47 | ||
| Bicarbonate | ~109 | ||
| ~ Estimated from hardness and ion balance — not directly measured by the water company. | |||
Additional info
| Hardness | 208.355 as CaCO₃ |
| Alkalinity | 89.6 as CaCO₃ |
| pH | 7.33 |
| Conductivity | 481 µS/cm |
| Source | Anglian Water |
| Data year | 2025 |
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
The buffering starts to become assertive: darker beer styles (porters, milds, brown ales) benefit from this level as it supports higher mash pH, but espresso will begin losing some of its brighter acidity, producing a rounder, heavier cup that flatters darker roasts while muting lighter ones.
Get the best from your water
NN5 tap water works well for espresso, brewing, baking, and aquarium use with little or no adjustment. It has too much mineral content for tea and horticulture; a bottled water blend is the better route for those.
Nearby areas
Data sourced from Anglian Water (2025). Looking for a specific address? Look up your full postcode for the most accurate result.