London includes the counties of Cheshire, Cumbria, Greater Manchester, Lancashire and Merseyside. So are these areas primarily supplied by hard or soft water? Let’s take a look!
What is the scale of hardness?
We can categorise water hardness into 3 different groups, the ppm stands for parts per million and refers to the amount of calcium carbonate and magnesium present in the water:
Soft to moderately soft water – 1 -100ppm
Medium to moderately hard water- 100-200ppm
Hard to very hard water – Over 200 ppm
Water is hard when it runs through or sits in areas with high mineral content. Water taken from certain sources is much more likely to be hard. Groundwater sources such as underground aquifers are a prime example of a hard water source.
Does Greater London have hard water?
London has hard to very hard water in almost all areas. This includes all 32 Boroughs and the City of London itself. There is some variation across the region with some areas having much harder water than others, Barnet and Islington have some of the hardest water in the city for example.

Which Water suppliers are active in this region?
There are 4 water suppliers across London. We’ll take a quick look at where they source their water from.
Affinity Water: Over 60% of Affinity’s water is sourced from groundwater taken directly from Aquifers. The remaining water comes from the Thames.
Essex and Suffolk Water: Most of Essex and Suffolks water is sourced from river systems with additional water coming from boreholes and surface water.
South East Water: South East water mostly uses groundwater from boreholes and wells with the rest coming from rivers and surface reservoirs.
Thames Water: Thames waters supply is sourced 56% from rivers and 35% from aquifers.
Final Thoughts
London is well known for its hard water, with very hard water being found across the city. If you are moving to London or already live there and do have limescale issues then you may want to look into a way to treat your water.
