UK Water Companies

All 16 major UK water companies ranked by average water quality score. Click any company to see detailed postcode-level data.

#	Company	Region	Customers	Avg Score	Areas
1	United Utilities	North West	7M	9.6/10	13
2	Yorkshire Water	Yorkshire	5M	9.5/10	11
3	South West Water	Devon and Cornwall	1.8M	9.5/10	4
4	Dŵr Cymru Welsh Water	Wales	3M	9.5/10	5
5	Northumbrian Water	North East	2.7M	9.3/10	5
6	Severn Trent	Midlands	8M	9.2/10	15
7	South East Water	South East England	2.2M	9.2/10	1
8	Southern Water	South East	4.7M	9/10	6
9	Anglian Water	East of England	4.5M	8.9/10	4
10	South Staffs Water	South Staffordshire and Cambridge	1.6M	8.8/10	2
11	Wessex Water	South West	2.8M	8.8/10	2
12	Bristol Water	Bristol and surrounding area	1.2M	8.4/10	8
13	Portsmouth Water	Hampshire and West Sussex	0.7M	8.4/10	2
14	Affinity Water	South East England	3.6M	8.4/10	3
15	Thames Water	London and Thames Valley	15M	8.2/10	30
16	Scottish Water	Scotland	5.4M	No data	0

Drinking water test data available