Water Hardness in Wales: Average 68 ppm

Water Hardness Across Wales

The average water hardness in the Wales region is 68 ppm, classified as slightly hard. Across 205 postcode districts, hardness ranges from 20 ppm to 120 ppm.

The region is served by Welsh Water (Dwr Cymru). Water hardness varies by county — see the breakdown below or check your specific postcode.

At 68 ppm, Wales ranks as slightly hard water nationally. Compare it against the 50 softest water areas in the UK.

Worth reading: our water softener guide covers the best options for Wales residents, and our limescale removal guide has quick fixes for kettles and taps.

By county

Counties in Wales

Sorted by hardness — see how your county compares.

County	Hardness	PPM	Level	Postcodes
Powys	113	113 ppm	Slightly Hard	8
Gwent	83	83 ppm	Slightly Hard	18
West Wales	72	72 ppm	Slightly Hard	51
Cardiff	68	68 ppm	Slightly Hard	36
North Wales	66	66 ppm	Slightly Hard	67
Mid Wales	43	43 ppm	Soft	25

Suppliers

Water Companies in Wales

Tap on a company for full coverage area and hardness data.

Welsh Water (Dwr Cymru)

68 ppm Slightly Hard

Test Your Water in Wales

At 68 ppm on average, your water is slightly hard. A home testing kit lets you verify the exact hardness for your postcode and check for other contaminants.

TESPERT 16-in-1 Water Testing Kit

From ~£10

Home water test strips that check hardness, pH, chlorine, lead, and 12 other parameters. Results in around 60 seconds. 125 strips per pack.

View on Amazon

FAQ

Common questions about Wales water

Is Wales's water hard or soft?

Wales is classified as slightly hard water, averaging 68 ppm across 205 postcode districts. Limescale build-up is minimal at this level, though individual postcodes vary.

Is tap water in Wales safe to drink?

Yes. All tap water in Wales meets UK drinking water standards. Hardness affects taste and limescale buildup but not safety.

Why is water in Wales slightly hard?

Water hardness in Wales depends on the geology — chalk and limestone aquifers dissolve calcium and magnesium into the supply, making it harder. Areas with sandstone or granite tend to be softer.

Does hard water affect boilers in Wales?

Over time, limescale acts as an insulator in heat exchangers, reducing efficiency by a few percentage points each year if untreated. A water softener can help protect your boiler.

What's the average water hardness in Wales?

The average water hardness across Wales is 68 ppm (parts per million), classified as slightly hard. It ranges from 20 ppm to 120 ppm across 205 postcode districts.

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Water hardness in Wales