- Essex and Suffolk Water
- SES Water
- Affinity Water
- Anglian Water
- Bournemouth Water
- Hafren Dyfrdwy
- Hartlepool Water
- Independent Water Networks
- Northumbrian Water
- Portsmouth Water
- Severn Trent Water
- South East Water
- South Staffs Water
- Southern Water
- Thames Water
- United Utilities
- Welsh Water
- Wessex Water
- Yorkshire Water
