County Durham · North East

Is Durham water hard or soft?

Moderately Hard at 126 ppm · 9 postcode districts

  • Supplier Northumbrian Water
  • County County Durham
  • Postcodes 9
Area average
126
ppm CaCO₃
Moderately Hard
Soft
Moderate
Hard
Very hard
0100200300400+

Durham water hardness at a glance

  1. Durham water is moderately hard, averaging 126 ppm across 9 postcode districts.
  2. That is 81 ppm below the UK average of 207 ppm.
  3. The hardest district is DH7 at 150 ppm; the softest is DH8 at 50 ppm.
  4. The supplier is Northumbrian Water.
  5. Limescale builds slowly at this level, so a softener is not usually needed.

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The average water hardness in Durham is 126 ppm, classified as moderately hard. Durham is served by Northumbrian Water, covering 9 postcode districts across County Durham in the North East region.

Hardness varies across the area. See the table below for a breakdown by postcode district. DH7 has the hardest water at 150 ppm, while DH8 is the softest at 50 ppm.

By postcode

Water Hardness by Postcode in Durham

Sorted by hardness. Tap a postcode for full details.

Postcode Water Company Hardness PPM Level
DH7 Northumbrian Water
150
150 ppm Moderately Hard
DH6 Northumbrian Water
149
149 ppm Moderately Hard
DH5 Northumbrian Water
148
148 ppm Moderately Hard
DH4 Northumbrian Water
147
147 ppm Moderately Hard
DH3 Northumbrian Water
146
146 ppm Moderately Hard
DH2 Northumbrian Water
145
145 ppm Moderately Hard
DH1 Northumbrian Water
144
144 ppm Moderately Hard
DH9 Northumbrian Water
51
51 ppm Soft
DH8 Northumbrian Water
50
50 ppm Soft
Suppliers

Water Companies Serving Durham

Tap for full coverage area and hardness data.

Northumbrian Water

101 ppm Slightly Hard

Each water company publishes its own hardness data, so you can cross-check the Durham figures here against the published hardness data from Northumbrian Water.

Water Hardness Guides

Learn more about water hardness and how to manage it.

What Is Water Hardness? Effects Solutions Water Softeners Limescale Removal

Test Your Water in Durham

At 126 ppm, your water is moderately hard. A home testing kit lets you verify the exact hardness and check for other contaminants.

TESPERT 16-in-1 Water Testing Kit

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

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FAQ

Common questions about Durham water

Is Durham water hard or soft?
Durham is classified as moderately hard, averaging 126 ppm across 9 postcode districts. Limescale build-up is minimal at this level, though individual postcodes vary.
Which postcode in Durham has the hardest water?
DH7 has the hardest water in Durham at 150 ppm, while DH8 is the softest at 50 ppm. See the full table above for every district.
Which water company supplies Durham?
Durham is supplied by Northumbrian Water, covering 9 postcode districts across County Durham.
Is tap water in Durham safe to drink?
Hardness is not a safety issue: the World Health Organization sets no health-based limit for water hardness, so hard and soft water are both fine to drink. Drinking water quality is regulated by the Drinking Water Inspectorate in England and Wales and the Drinking Water Quality Regulator in Scotland, and your water company publishes test results for your area.
Does Durham have any harder-water postcodes?
DH7 is the hardest district at 150 ppm (moderately hard), though most of Durham averages 126 ppm.
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