Drinking Water Inspectorate (DWI)
DWI’s main job is to check that the water companies in England and Wales supply safe drinking water that is acceptable to consumers and meets the standards set down in law.
Every day, tap water is tested by the water companies. Our inspectors independently check these tests and audit water company laboratories. If any one of the millions of tests each year fails the standards then our inspectors use their powers to require the water company to make the necessary improvements to drinking water quality. Our inspectors go out on site to check that improvement work is completed on time. They also inspect that the aspects of water operations which ensure drinking water is safe at all times.
Very occasionally things go wrong. When this happens, it is our job to investigate the operational incident and provide an independent report of the cause with recommendations on how to prevent similar events from happening again. Sometimes our investigations of incidents lead to a water company being prosecuted. In addition, when a water company fails to resolve a drinking water quality complaint then the consumer can come to us for help.
The Chief Inspector of Drinking Water is appointed by the Secretary of State for Environment, Food and Rural Affairs and Welsh Ministers and acts independently on behalf of these authorities. Certain powers are vested directly in the Chief Inspector of Drinking Water. The legislation is set out in the Water Industry Act 1991 as amended by the Water Act 2003. Equivalent regulators exist in Scotland and Northern Ireland.
To find out more about the Drinking Water Inspectorate, click here.