Water Hardness in Cornwall

Water Hardness Across Cornwall

The average water hardness in Cornwall is 91 ppm, classified as slightly hard. Across 23 postcode districts in the South West region, hardness ranges from 69 ppm to 109 ppm.

Cornwall is served by South West Water. With slightly hard water, limescale is unlikely to be a major concern in most homes.

Hardness across Cornwall ranges from 69 ppm to 109 ppm by postcode district. The county spans 1 towns and 23 postcode districts in total.

At 91 ppm, Cornwall ranks as slightly hard water nationally. Compare it against the 50 softest water areas in the UK.

By town

Towns in Cornwall

Sorted by hardness — tap a town for full details.

Town	Hardness	PPM	Level
Truro	91	91 ppm	Slightly Hard

Suppliers

Water Companies in Cornwall

Companies supplying water to this county.

South West Water

80 ppm Slightly Hard

All postcodes

Postcodes in Cornwall

Every postcode district in the county, sorted by hardness.

Postcode	Town	Hardness	PPM	Level
TR27	Hayle	109	109 ppm	Slightly Hard
TR26	St Ives	108	108 ppm	Slightly Hard
TR9	St Columb	107	107 ppm	Slightly Hard
TR8	Newquay	106	106 ppm	Slightly Hard
TR7	Newquay	105	105 ppm	Slightly Hard
TR6	Perranporth	104	104 ppm	Slightly Hard
TR21	Isles Of Scilly	103	103 ppm	Slightly Hard
TR5	St Agnes	103	103 ppm	Slightly Hard
TR20	Penzance	102	102 ppm	Slightly Hard
TR4	Truro	102	102 ppm	Slightly Hard
TR3	Truro	101	101 ppm	Slightly Hard
TR2	Truro	100	100 ppm	Slightly Hard
TR1	Truro	99	99 ppm	Slightly Hard
TR19	Penzance	78	78 ppm	Slightly Hard
TR18	Penzance	77	77 ppm	Slightly Hard
TR17	Marazion	76	76 ppm	Slightly Hard
TR16	Redruth	75	75 ppm	Slightly Hard
TR15	Redruth	74	74 ppm	Slightly Hard
TR14	Camborne	73	73 ppm	Slightly Hard
TR13	Helston	72	72 ppm	Slightly Hard
TR12	Helston	71	71 ppm	Slightly Hard
TR11	Falmouth	70	70 ppm	Slightly Hard
TR10	Penryn	69	69 ppm	Slightly Hard

Test Your Water in Cornwall

At 91 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

Water Hardness in Cornwall: Common Questions

Is the water in Cornwall hard or soft?

Cornwall has slightly hard water, averaging 91 ppm across 23 postcode districts. Limescale build-up is minimal at this level, though individual postcodes vary.

Where is the hardest water in Cornwall?

Across Cornwall, water hardness ranges from 69 ppm to 109 ppm by postcode district.

Which water company supplies Cornwall?

Cornwall is supplied by South West Water. You can check each supplier's reported hardness figures on their water company page.

Do I need a water softener in Cornwall?

At 91 ppm, Cornwall has soft water and a whole-house softener is not needed.

What is the average water hardness in Cornwall?

The average water hardness in Cornwall is 91 ppm (parts per million), classified as slightly hard. It ranges from 69 ppm to 109 ppm across 23 postcode districts in the South West region.

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