Tap Water in CM6
Thaxted — Affinity Water
Tap water in Thaxted, supplied by Affinity Water, has the character of a chalk aquifer source, typical of southern and eastern England. It’s very hard, among the hardest tap water in England, with a total hardness of 440 mg/L as CaCO₃. This is notably hard water, among the highest-mineral tap water in England.
Mineral composition
| mg/L | |
|---|---|
| Calcium | 176 |
| Magnesium | 0 |
| Sodium | 24 |
| Sulfate | 126 |
| Chloride | 42 |
| Bicarbonate | 372 |
Additional info
| Hardness | 440 as CaCO₃ |
| Alkalinity | 304.9 as CaCO₃ |
| pH | 7 |
| Conductivity | awaiting data |
| Source | Affinity Water |
| Data year | 2024 |
What this means
Kettle & appliances
Severe and rapid limescale buildup. Kettles need descaling weekly. Boilers, heating systems, and appliances are all at risk of reduced efficiency and premature failure without water treatment. A softener is more or less essential for protecting household infrastructure.
Espresso
Scale protection is non-negotiable: without filtration or treatment, boilers and heating elements will accumulate deposits quickly. In the cup, lighter roasts are a write-off (no acidity survives this level of buffering). Very dark roasts with milk remain viable, following the same logic as the hard tier, but even here the water’s heaviness can dominate. For anything origin-forward or light-roasted, the water needs treating or replacing entirely.
Filter & pour-over
At this level, the water overwhelms filter brewing. The high mineral content and buffering flatten the cup to the point where roast origin and varietal character are essentially absent. Even darker roasts taste dense and chalky. Treating or replacing the water is a prerequisite for any filter method.
Drinking & cooking
A strong mineral presence. Many people describe it as chalky or heavy. Surface scum on tea and coffee is very likely. Hard water at this level can noticeably affect cooking (pulses may take longer to soften, for instance) and will leave mineral deposits on virtually everything it touches.
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.
Get the best from your water
CM6 tap water works well for brewing with little or no adjustment. It has too much mineral content for espresso, baking, aquarium use, tea, and horticulture; a bottled water blend is the better route for those.
Nearby areas
Data sourced from Affinity Water (2024). Looking for a specific address? Look up your full postcode for the most accurate result.