Water quality in London
Water quality across Greater London, supplied primarily by Thames Water and Affinity Water.
According to TapWater.uk's analysis, London scores 8.4/10 for drinking water quality in 2026, based on data from 80 postcode districts.
8.4
Avg score /10
80
Areas tested
1
Suppliers
0
PFAS detections
Tap water in London has an average safety score of 8.4 out of 10 based on testing across 80 postcode districts. Water is supplied by Thames Water. The overall water quality is good. Data is sourced from the Environment Agency and water company testing via the Stream Water Data Portal.
Try your postcode — e.g. SW1A, M1, B1
Cities in London
Average water quality score by city.
Water suppliers
All postcode areas in London
Every postcode district we monitor in this region.