Water Hardness – How Hard is My Water?

“Do I have hard water?” and “how hard is my water?” are two questions that are commonly searched online. Around 60% of the UK is classed as having hard or very hard water and are facing scale problems in the home. This hard water guide will provide all the information you need to find out about water hardness for yourself.

1. What is hard water & what causes it?
2. Hard water limescale problems
3. How is hard water measured?
4. How hard is my water?
4a. UK towns and cities with the hardest water.
4b. UK counties with the hardest water.
5. Ask your water providers about hard water.
6. How to remove hard water.

1. What is Hard Water & What Causes It?

Hard water is water which contains a high amount of dissolved calcium and magnesium minerals. When rain water falls – it is naturally soft. But if it falls and lands in an area with chalk (calcium carbonate) or other porous rock such as limestone, this causes hard water. This is because, when rain water lands it penetrates the ground, and moves through the limestone and chalk. When it does this, it dissolves some of these rocks and their minerals, becoming hard.

The hardness of water is therefore determined by the area in which you live and the ground’s rock and mineral content. For example, in areas such as the South East of England and London, the calcium and magnesium in water levels are very high. Whereas other areas such as wales has soft water.

Hard Water Map of Uk
Image Credit: Scale Guard

2. Hard Water Limescale Problems

So why has hard water got such a bad name and reputation? Well, hard water and its minerals, calcium and magnesium, cause limescale. And limescale can cause a whole host of problems in the home – some of which can be permanent.

Limescale can cause:

  • Blocked taps and shower heads.
  • Blockages in the heating and water pipes, which can result in higher energy bills and lower water pressure.
  • Boiler breakdowns and expensive repairs.
  • Limescale on surfaces and glass screens, which can leave permanent marks if not cleaned daily.
  • Permanent stains in your bathroom and kitchen.
  • Scale deposits and white marks on cutlery, dishes and glassware.
  • Damages to home appliances, such as the washing machine and dishwasher.
  • Scale deposits in your water – especially cups of tea.
  • Eczema and dry skin. Hard water irritates the skins outer barrier, causing sensitive skin and irritation.
  • Frizzy and damaged hair that appears greasy.
  • A home which requires more cleaning and maintenance.
  • A lack of lather in the bath and shower. Hard water and limescale doesn’t react well with soap. You won’t experience a lather and you may find yourself using way more shampoo and shower gel.
  • Clothes that still seem dirty even after washing. Hard water requires more detergent and soap powder to effectively clean your clothes.
  • Expensive household bills, due to the cost of more cleaning products and washing powders.

3. How is Water Hardness Measured?

Water hardness is measured through the amount of hard water mineral deposits that are dissolved in the water and is recorded in parts per million (ppm). This measurement is then compared on the below scale to give a level of hardness.

Water HardnessPPM Reading
Soft0 – 50
Moderately Soft51 – 100
Slightly Hard101 – 150
Moderately Hard151 – 200
Hard201 – 275
Very Hard276 – 350
Extremely Hard350 +
Hardness Measurements Scale

4. How Hard is My Water?

So how hard is you water? This is entirely determined by where you live, and the hardness can really vary from postcode to postcode. If you have signs of hard water – the chances are you already know it’s hard. The tables below outline the hardest areas of water in the UK. You can also find out by contacting your water provider.

4a. UK towns and cities with the hardest water

Town / CityWater Hardness Level
BathVery hard
Hemel HempsteadVery hard 
Milton KeynesVery hard 
SloughVery hard 
SwindonVery hard
Cities with hardest water

4b. UK counties with the hardest water

CountyWater Hardness Level
BedfordshireHard – very hard
BerkshireHard – very hard
BuckinghamshireHard – very hard
CambridgeshireHard – very hard
DorsetHard – very hard
EssexHard – very hard
GloucestershireHard – very hard
Greater LondonHard – very hard
HampshireHard – very hard
HertfordshireHard – very hard
KentHard – very hard
OxfordshireHard – very hard
SurreyHard – very hard
SussexHard – very hard
WiltshireHard – very hard
Counties with the hardest water

5. Ask Your Water Providers About Hard Water

Affinity Water here
Anglian Water here
Bournemouth Water here
Bristol Water here
Cambridge Water here
Cholderton and District Water here
Dee Valley Water here
Dwr Cymru – Welsh Water here
Essex and Suffolk Water here
Northumbrian Water here
For Portsmouth Water here
Drinking Water Quality Regulator for Scotland here
Severn Trent Water here
South East Water here
South Staffs Water, click here
South West Water, here
Southern Water here
Sutton and East Surrey Water here
Thames Water here
United Utilities Water, here
Wessex Water here
Yorkshire Water here
Water providers in the UK

6. How to Remove Hard Water

Now you know how hard your water is – how can you get rid of it! The only way to permanently remove hard water from your home is using a water softener. A water softener works to effectively filter calcium and magnesium out of your water, removing limescale and its deposits. To find out more, check out our water softener buying guide.

Water Softener Buying Guide

Find out how to choose a water softener to remove hard water and limescale for good.