UK Water Utility AuthorityDWI Water Quality VerifiedUpdated: 16 September 2025

Wessex Water Water Hardness

Top-performing water and sewerage company serving 2.8 million customers in the South West of England. Discover network-wide PPM ratings, chalk aquifer vs reservoir water sources, and local appliance calibration guidelines.

Quick Search Verdict

Is Wessex Water Water Hard or Soft?

Hard Water
290 PPM
20.3° Clark

Yes, tap water supplied by Wessex Water across Bath, Somerset, Wiltshire, and Dorset is hard to very hard, averaging 290 PPM (20.3° Clark). Rich in calcium carbonate dissolved from famous Jurassic oolitic limestone (Bath Stone) and southern chalk hills.

Primary Abstraction: Wessex Water abstracts roughly 75% of drinking water from groundwater springs and boreholes sunk into limestone and chalk strata, with the remainder from lowland reservoirs.

Regional Limescale Risk
Severe Risk+45% vs UK avg
Serving 72 postal districts across Bath, Bristol, Somerset, Wiltshire, and Dorset.
Network Average
290 mg/L
20.3° Clark (29.0°fH / 16.2°dH)
Network Coverage
72 Outcodes
Mapped across 240 local sectors
Softest Outcode
290 PPM (Hard)
Hardest Outcode
290 PPM (Hard)

Where Does Wessex Water Water Come From?

Water hardness across Wessex 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: 75% Groundwater boreholes and springs in Jurassic oolitic limestone and southern chalk.

Major population centers served by Wessex Water include: Bath, Bristol, Dorchester, Salisbury, Bournemouth, Trowbridge, Taunton. If your water bill comes from Wessex Water, your tap water is certified by the Drinking Water Inspectorate (DWI) and adheres to all British potable safety standards.

DWI Technical Reference

  • Supplier Codewessex-water
  • Typical Range250 – 315 PPM (mg/L CaCO3)
  • Source Classificationchalk groundwater
  • Coverage RegionBath, Bristol, Somerset, Wiltshire, and Dorset

Appliance Care & Heating Compliance for Wessex Water Customers

Kettle Descaling Protocol

Descale every 3–4 weeks with citric acid powder. Heavy scale crust reduces heating speed and taints tea.

Dishwasher Salt Calibration

Set to Level 4 or H05. Never rely solely on all-in-one tablets in Wessex Water territory.

Combi Boiler Protection (BS 7593)

Comply with Part L building regulations by fitting an approved inline scale reducer or water softener.

Expert Softener Recommendation: An ion-exchange water softener provides dramatic relief for Bath and Somerset households, keeping shower glass clear and preventing boiler breakdowns.

Wessex Water Network Postcode Outcodes (72)

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

BA1
290 PPMHard
10 sectors
BA2
290 PPMHard
7 sectors
BA7
290 PPMHard
1 sector
BA8
290 PPMHard
1 sector
BA9
290 PPMHard
3 sectors
BA10
290 PPMHard
1 sector
BA12
290 PPMHard
6 sectors
BA13
290 PPMHard
4 sectors
BA14
290 PPMHard
6 sectors
BA15
290 PPMHard
3 sectors
BA20
290 PPMHard
3 sectors
BA21
290 PPMHard
3 sectors
BA22
290 PPMHard
3 sectors
BH12
290 PPMHard
3 sectors
BH13
290 PPMHard
1 sector
BH14
290 PPMHard
4 sectors
BH15
290 PPMHard
5 sectors
BH16
290 PPMHard
2 sectors
BH17
290 PPMHard
4 sectors
BH18
290 PPMHard
2 sectors
BH19
290 PPMHard
4 sectors
BH20
290 PPMHard
5 sectors
BH21
290 PPMHard
1 sector
DT1
290 PPMHard
4 sectors
DT2
290 PPMHard
4 sectors
DT3
290 PPMHard
3 sectors
DT4
290 PPMHard
5 sectors
DT5
290 PPMHard
3 sectors
DT6
290 PPMHard
5 sectors
DT8
290 PPMHard
1 sector
DT9
290 PPMHard
5 sectors
DT10
290 PPMHard
3 sectors
DT11
290 PPMHard
5 sectors
SN9
290 PPMHard
2 sectors
SN10
290 PPMHard
6 sectors
SN11
290 PPMHard
4 sectors
SN12
290 PPMHard
4 sectors
SN13
290 PPMHard
3 sectors
SN14
290 PPMHard
3 sectors
SN15
290 PPMHard
5 sectors
SN16
290 PPMHard
2 sectors
SP1
290 PPMHard
3 sectors
SP2
290 PPMHard
5 sectors
SP3
290 PPMHard
3 sectors
SP4
290 PPMHard
7 sectors
SP5
290 PPMHard
3 sectors
SP7
290 PPMHard
4 sectors
SP8
290 PPMHard
3 sectors
SP11
290 PPMHard
1 sector
TA1
290 PPMHard
6 sectors
TA2
290 PPMHard
3 sectors
TA3
290 PPMHard
3 sectors
TA4
290 PPMHard
5 sectors
TA5
290 PPMHard
2 sectors
TA6
290 PPMHard
6 sectors
TA7
290 PPMHard
3 sectors
TA9
290 PPMHard
1 sector
TA10
290 PPMHard
3 sectors
TA11
290 PPMHard
3 sectors
TA12
290 PPMHard
1 sector
TA13
290 PPMHard
1 sector
TA14
290 PPMHard
1 sector
TA15
290 PPMHard
1 sector
TA16
290 PPMHard
1 sector
TA17
290 PPMHard
1 sector
TA18
290 PPMHard
3 sectors
TA19
290 PPMHard
2 sectors
TA20
290 PPMHard
5 sectors
TA21
290 PPMHard
4 sectors
TA22
290 PPMHard
1 sector
TA23
290 PPMHard
1 sector
TA24
290 PPMHard
5 sectors
Local Installer Quote Network

Living in a Hard Water Zone (TA9 averages 290 PPM)? Compare Approved Local Installers

Get up to 3 free, no-obligation quotes from WRAS-approved water softener installers and heating engineers serving Wessex Water Service Area.

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Frequently Asked Questions: Wessex Water Water Hardness

How hard is water in the Wessex Water region?

Wessex Water tap water averages between 250 and 315 PPM (17.5° to 22.0° Clark), classifying it firmly as hard to very hard.

Why is water so hard in Bath and Somerset?

The region sits on Jurassic oolitic limestone (Bath Stone) and the chalk hills of Salisbury Plain. Rain dissolving through these rocks creates mineral-dense groundwater.

What dishwasher setting should I use in Wessex Water areas?

Set your dishwasher water hardness dial to H05 on Bosch/Neff/Siemens, or Level 4 on Beko, and ensure granular salt is consistently replenished.

Do boilers break down faster in Wessex Water areas?

Yes, limescale accumulation on secondary plate heat exchangers causes kettling noises and temperature fluctuations, requiring BS 7593 scale inhibitors.