South West · County

Water hardness in Cornwall

Average 91 ppm across 23 postcodes and 1 towns.

  • Range 69–109 ppm
  • Towns 1
  • Suppliers South West Water
County average
91
ppm CaCO₃
Slightly Hard
Soft
Moderate
Hard
Very hard
0100200300400+
91
Avg ppm
69
Min ppm
109
Max ppm
23
Postcodes

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.

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

Hard Water Guides

Learn more about water hardness and how to manage it.

What Is Water Hardness? Hard Water Effects Solutions
All counties in South West · Hardest water areas · Softest water areas · Hard water solutions

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