How Sudbury compares
At 378 mg/L (26.5 °Clark), Sudbury is 56% above the median of the 411 English towns on this map (243 mg/L). It ranks 8 of 411 for hardness (1 is the hardest).
Water hardness in Sudbury
Sudbury has very hard water: limescale builds up quickly, so descale often and protect your boiler.
Data
| Value | 378 mg/L calcium carbonate 26.5 °Clark, 21.2 °dH |
|---|---|
| Band | very hard |
| Area | Suffolk |
| Population | 23,912 |
| Water company | Anglian Water |
| Postcode checked | CO10 1RA (Sudbury and Great Cornard PWSZ) |
| Checked | 21 Oct 2026 |
| From the source | “"Calcium Carbonate":"378.215" mg/l CaCO3,"degrees Clark":"26.324","class":"very hard"” |
What it means for your home
Hard water drops a lot of scale when it is heated: in the kettle, the shower head and the element of an immersion heater or washing machine. Chalky rings on taps and spotty glasses are normal.
Set the dishwasher for hard water, dose detergent for your band and descale regularly. If you have a combi boiler, ask about a scale reducer at its next service. Hard water is safe to drink.
How often to descale
As a rule of thumb for very hard water, kettles and shower heads need descaling every three or four weeks. Descale whenever you see scale building up.
Common questions
Is hard water bad for you?
No. Hard water carries calcium and magnesium, minerals the body uses. Whether tap water is safe depends on germs and pollutants, which water companies test for, not on hardness.
Do I need a water softener in Sudbury?
The water company's figure for Sudbury is 378 mg/L (26.5 °Clark), which is very hard water. Usually not straight away. Set the dishwasher, dose detergent for your band and descale regularly. Get quotes for a softener only if scale is clearly damaging your boiler or appliances.
How do I find the value for my address?
Use your water company's postcode checker. Hardness can differ between districts, so check your own postcode, or test with strips or a drop test.
Nearby towns
Colchester 20 km Haverhill 21 km Braintree 22 km Bury St Edmunds 23 km Stowmarket 25 km Ipswich 29 km Newmarket 32 km Harwich 39 km