UK Water Utility AuthorityDWI Water Quality VerifiedUpdated: 4 March 2025

Anglian Water Water Hardness

Managing the largest geographic licensed water and water recycling area in England and Wales. Discover network-wide PPM ratings, chalk aquifer vs reservoir water sources, and local appliance calibration guidelines.

Quick Search Verdict

Is Anglian Water Water Hard or Soft?

Very Hard Water
310 PPM
21.7° Clark

Yes, Anglian Water supplies some of the hardest drinking water in the British Isles, averaging 310 PPM and frequently exceeding 350 PPM. East Anglia sits atop a massive Cretaceous chalk aquifer with minimal annual rainfall, resulting in extreme mineral saturation.

Primary Abstraction: Half of public tap water is pumped from deep agricultural and chalk boreholes across Norfolk, Suffolk, and Cambridgeshire; the other half is stored in lowland reservoirs like Rutland Water and Grafham Water.

Regional Limescale Risk
Severe Risk+55% vs UK avg
Serving 215 postal districts across East Anglia, Bedfordshire, Northamptonshire & Lincolnshire.
Network Average
310 mg/L
21.7° Clark (31.0°fH / 17.4°dH)
Network Coverage
215 Outcodes
Mapped across 775 local sectors
Softest Outcode
310 PPM (Very Hard)
Hardest Outcode
310 PPM (Very Hard)

Where Does Anglian Water Water Come From?

Water hardness across Anglian Water's licensed territory is strictly determined by regional hydrogeology. Rainwater is naturally soft when it falls from clouds, but absorbs dissolved minerals as it percolates through soil and rock layers before municipal abstraction.

Primary Catchment Profile: 50% Underground Cretaceous chalk aquifers, 50% Surface reservoirs fed by lowland rivers.

Major population centers served by Anglian Water include: Norwich, Ipswich, Cambridge, Peterborough, Northampton, Milton Keynes, Colchester. If your water bill comes from Anglian Water, your tap water is certified by the Drinking Water Inspectorate (DWI) and adheres to all British potable safety standards.

DWI Technical Reference

  • Supplier Codeanglian-water
  • Typical Range290 – 360+ PPM (mg/L CaCO3)
  • Source Classificationchalk groundwater
  • Coverage RegionEast Anglia, Bedfordshire, Northamptonshire & Lincolnshire

Appliance Care & Heating Compliance for Anglian Water Customers

Kettle Descaling Protocol

Descale every 2 weeks. Thick stone-like calcium crust forms rapidly without frequent citric acid treatment.

Dishwasher Salt Calibration

Set to maximum setting H06 or H07 (Bosch) or Level 5 (Beko). Always maintain granular salt to avoid permanent glass etching.

Combi Boiler Protection (BS 7593)

Mandatory Part L scale prevention (>200 PPM). A 1.2mm scale layer reduces heating efficiency by 10%, adding £150+ to annual gas bills.

Expert Softener Recommendation: A dual-cylinder ion-exchange water softener is virtually standard in East Anglian homes, paying for itself within 3–4 years through appliance longevity and energy savings.

Anglian Water Network Postcode Outcodes (215)

Search and explore official DWI water hardness readings across all postal districts supplied by Anglian Water.

CB6
310 PPMVery Hard
3 sectors
CB7
310 PPMVery Hard
5 sectors
CB8
310 PPMVery Hard
5 sectors
CB9
310 PPMVery Hard
5 sectors
CB25
310 PPMVery Hard
1 sector
CM3
310 PPMVery Hard
1 sector
CM6
310 PPMVery Hard
1 sector
CM7
310 PPMVery Hard
7 sectors
CM77
310 PPMVery Hard
3 sectors
CO1
310 PPMVery Hard
3 sectors
CO2
310 PPMVery Hard
4 sectors
CO3
310 PPMVery Hard
5 sectors
CO4
310 PPMVery Hard
6 sectors
CO5
310 PPMVery Hard
5 sectors
CO6
310 PPMVery Hard
5 sectors
CO7
310 PPMVery Hard
1 sector
CO8
310 PPMVery Hard
1 sector
CO9
310 PPMVery Hard
5 sectors
CO10
310 PPMVery Hard
8 sectors
CO11
310 PPMVery Hard
1 sector
DN10
310 PPMVery Hard
2 sectors
DN15
310 PPMVery Hard
6 sectors
DN16
310 PPMVery Hard
3 sectors
DN17
310 PPMVery Hard
3 sectors
DN18
310 PPMVery Hard
3 sectors
DN19
310 PPMVery Hard
2 sectors
DN20
310 PPMVery Hard
4 sectors
DN21
310 PPMVery Hard
6 sectors
DN22
310 PPMVery Hard
8 sectors
DN31
310 PPMVery Hard
4 sectors
DN32
310 PPMVery Hard
4 sectors
DN33
310 PPMVery Hard
3 sectors
DN34
310 PPMVery Hard
2 sectors
DN35
310 PPMVery Hard
4 sectors
DN36
310 PPMVery Hard
2 sectors
DN37
310 PPMVery Hard
4 sectors
DN38
310 PPMVery Hard
1 sector
DN39
310 PPMVery Hard
1 sector
DN40
310 PPMVery Hard
4 sectors
DN41
310 PPMVery Hard
2 sectors
IP1
310 PPMVery Hard
7 sectors
IP2
310 PPMVery Hard
3 sectors
IP3
310 PPMVery Hard
3 sectors
IP4
310 PPMVery Hard
5 sectors
IP5
310 PPMVery Hard
4 sectors
IP6
310 PPMVery Hard
3 sectors
IP7
310 PPMVery Hard
4 sectors
IP8
310 PPMVery Hard
2 sectors
IP9
310 PPMVery Hard
2 sectors
IP10
310 PPMVery Hard
1 sector
IP11
310 PPMVery Hard
8 sectors
IP12
310 PPMVery Hard
5 sectors
IP13
310 PPMVery Hard
2 sectors
IP14
310 PPMVery Hard
6 sectors
IP20
310 PPMVery Hard
1 sector
IP21
310 PPMVery Hard
1 sector
IP22
310 PPMVery Hard
4 sectors
IP23
310 PPMVery Hard
1 sector
IP24
310 PPMVery Hard
4 sectors
IP25
310 PPMVery Hard
3 sectors
IP26
310 PPMVery Hard
2 sectors
IP27
310 PPMVery Hard
3 sectors
IP28
310 PPMVery Hard
7 sectors
IP29
310 PPMVery Hard
2 sectors
IP30
310 PPMVery Hard
2 sectors
IP31
310 PPMVery Hard
3 sectors
IP32
310 PPMVery Hard
2 sectors
IP33
310 PPMVery Hard
4 sectors
IP98
310 PPMVery Hard
2 sectors
LE16
310 PPMVery Hard
1 sector
LN1
310 PPMVery Hard
6 sectors
LN2
310 PPMVery Hard
5 sectors
LN3
310 PPMVery Hard
2 sectors
LN4
310 PPMVery Hard
4 sectors
LN5
310 PPMVery Hard
5 sectors
LN6
310 PPMVery Hard
8 sectors
LN7
310 PPMVery Hard
1 sector
LN8
310 PPMVery Hard
5 sectors
LN9
310 PPMVery Hard
3 sectors
LN10
310 PPMVery Hard
2 sectors
LN11
310 PPMVery Hard
5 sectors
LN12
310 PPMVery Hard
3 sectors
LN13
310 PPMVery Hard
3 sectors
LU5
310 PPMVery Hard
1 sector
LU7
310 PPMVery Hard
7 sectors
MK1
310 PPMVery Hard
2 sectors
MK2
310 PPMVery Hard
2 sectors
MK3
310 PPMVery Hard
4 sectors
MK4
310 PPMVery Hard
4 sectors
MK5
310 PPMVery Hard
3 sectors
MK6
310 PPMVery Hard
5 sectors
MK7
310 PPMVery Hard
3 sectors
MK8
310 PPMVery Hard
4 sectors
MK9
310 PPMVery Hard
4 sectors
MK10
310 PPMVery Hard
4 sectors
MK11
310 PPMVery Hard
5 sectors
MK12
310 PPMVery Hard
2 sectors
MK13
310 PPMVery Hard
4 sectors
MK14
310 PPMVery Hard
3 sectors
MK15
310 PPMVery Hard
3 sectors
MK16
310 PPMVery Hard
4 sectors
MK17
310 PPMVery Hard
4 sectors
MK18
310 PPMVery Hard
9 sectors
MK19
310 PPMVery Hard
2 sectors
MK20
310 PPMVery Hard
1 sector
MK40
310 PPMVery Hard
5 sectors
MK41
310 PPMVery Hard
6 sectors
MK42
310 PPMVery Hard
6 sectors
MK43
310 PPMVery Hard
7 sectors
MK44
310 PPMVery Hard
4 sectors
MK45
310 PPMVery Hard
7 sectors
MK46
310 PPMVery Hard
2 sectors
MK77
310 PPMVery Hard
1 sector
NG22
310 PPMVery Hard
1 sector
NG23
310 PPMVery Hard
1 sector
NG31
310 PPMVery Hard
5 sectors
NG32
310 PPMVery Hard
3 sectors
NG33
310 PPMVery Hard
2 sectors
NG34
310 PPMVery Hard
6 sectors
NN1
310 PPMVery Hard
6 sectors
NN2
310 PPMVery Hard
4 sectors
NN3
310 PPMVery Hard
8 sectors
NN4
310 PPMVery Hard
8 sectors
NN5
310 PPMVery Hard
5 sectors
NN6
310 PPMVery Hard
5 sectors
NN7
310 PPMVery Hard
5 sectors
NN8
310 PPMVery Hard
7 sectors
NN9
310 PPMVery Hard
2 sectors
NN10
310 PPMVery Hard
5 sectors
NN11
310 PPMVery Hard
9 sectors
NN12
310 PPMVery Hard
4 sectors
NN13
310 PPMVery Hard
4 sectors
NN14
310 PPMVery Hard
5 sectors
NN15
310 PPMVery Hard
4 sectors
NN16
310 PPMVery Hard
4 sectors
NN17
310 PPMVery Hard
6 sectors
NN18
310 PPMVery Hard
3 sectors
NN29
310 PPMVery Hard
1 sector
NR1
310 PPMVery Hard
4 sectors
NR2
310 PPMVery Hard
4 sectors
NR3
310 PPMVery Hard
4 sectors
NR4
310 PPMVery Hard
2 sectors
NR5
310 PPMVery Hard
4 sectors
NR6
310 PPMVery Hard
3 sectors
NR7
310 PPMVery Hard
4 sectors
NR8
310 PPMVery Hard
3 sectors
NR9
310 PPMVery Hard
3 sectors
NR10
310 PPMVery Hard
3 sectors
NR11
310 PPMVery Hard
3 sectors
NR12
310 PPMVery Hard
4 sectors
NR13
310 PPMVery Hard
4 sectors
NR14
310 PPMVery Hard
3 sectors
NR15
310 PPMVery Hard
2 sectors
NR16
310 PPMVery Hard
2 sectors
NR17
310 PPMVery Hard
2 sectors
NR18
310 PPMVery Hard
3 sectors
NR19
310 PPMVery Hard
3 sectors
NR20
310 PPMVery Hard
3 sectors
NR21
310 PPMVery Hard
5 sectors
NR22
310 PPMVery Hard
1 sector
NR23
310 PPMVery Hard
1 sector
NR24
310 PPMVery Hard
1 sector
NR25
310 PPMVery Hard
3 sectors
NR26
310 PPMVery Hard
2 sectors
NR27
310 PPMVery Hard
3 sectors
NR28
310 PPMVery Hard
3 sectors
NR29
310 PPMVery Hard
1 sector
NR34
310 PPMVery Hard
1 sector
NR35
310 PPMVery Hard
1 sector
NR99
310 PPMVery Hard
1 sector
OX17
310 PPMVery Hard
1 sector
PE1
310 PPMVery Hard
6 sectors
PE2
310 PPMVery Hard
6 sectors
PE3
310 PPMVery Hard
4 sectors
PE4
310 PPMVery Hard
3 sectors
PE5
310 PPMVery Hard
1 sector
PE6
310 PPMVery Hard
5 sectors
PE7
310 PPMVery Hard
7 sectors
PE8
310 PPMVery Hard
4 sectors
PE9
310 PPMVery Hard
5 sectors
PE10
310 PPMVery Hard
4 sectors
PE11
310 PPMVery Hard
8 sectors
PE12
310 PPMVery Hard
6 sectors
PE13
310 PPMVery Hard
5 sectors
PE14
310 PPMVery Hard
5 sectors
PE15
310 PPMVery Hard
4 sectors
PE16
310 PPMVery Hard
2 sectors
PE19
310 PPMVery Hard
8 sectors
PE20
310 PPMVery Hard
3 sectors
PE21
310 PPMVery Hard
6 sectors
PE22
310 PPMVery Hard
4 sectors
PE23
310 PPMVery Hard
3 sectors
PE24
310 PPMVery Hard
2 sectors
PE25
310 PPMVery Hard
4 sectors
PE28
310 PPMVery Hard
4 sectors
PE29
310 PPMVery Hard
6 sectors
PE30
310 PPMVery Hard
6 sectors
PE31
310 PPMVery Hard
3 sectors
PE32
310 PPMVery Hard
2 sectors
PE33
310 PPMVery Hard
2 sectors
PE34
310 PPMVery Hard
2 sectors
PE35
310 PPMVery Hard
1 sector
PE36
310 PPMVery Hard
3 sectors
PE37
310 PPMVery Hard
2 sectors
PE38
310 PPMVery Hard
3 sectors
SG5
310 PPMVery Hard
1 sector
SG15
310 PPMVery Hard
1 sector
SG16
310 PPMVery Hard
1 sector
SG17
310 PPMVery Hard
2 sectors
SG18
310 PPMVery Hard
4 sectors
SG19
310 PPMVery Hard
3 sectors
TS24
310 PPMVery Hard
5 sectors
TS25
310 PPMVery Hard
5 sectors
TS26
310 PPMVery Hard
3 sectors
TS27
310 PPMVery Hard
1 sector
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Frequently Asked Questions: Anglian Water Water Hardness

How hard is water in the Anglian Water region?

Anglian Water tap water is classified as very hard to extremely hard, ranging between 290 and 360+ PPM (20.3° to 25.2° Clark). Norwich, Ipswich, and Bury St Edmunds routinely record some of the highest mineral counts in the UK.

Why is East Anglia water so hard?

East Anglia is underlain by the primary English Chalk aquifer and receives the lowest rainfall in the UK. Rain remains underground in chalk strata for prolonged periods, dissolving high amounts of calcium and magnesium bicarbonate.

What dishwasher setting should I use in Anglian Water territory?

Select the highest hardness setting on your appliance (H06/H07 on Bosch/Siemens, or Level 5 on Beko). Never run appliances without salt in this region.

Will hard water damage my boiler in Norfolk or Suffolk?

Yes, combi boiler secondary heat exchangers can choke with scale within 12 to 18 months in untreated 330+ PPM water. Fitting an inline scale inhibitor is mandatory under Building Regulations Part L.