Water quality testing

Water quality testing ensures that all UK tap water meets the expected standards.

We’re regulated

All water companies carry out water quality monitoring, and must closely monitor their water before, during and after the treatment process to make sure it meets the stringent water quality standards in the Water Supply (Water Quality) Regulations 2016 (as amended 2018). This ensures that all UK tap water meets the expected standards.

Sampling at source

We regularly visit our sources and treatment works to test the water by taking samples, this ensures the treatment process is working correctly and meets these tight standards.

The results of these samples are assessed by the Drinking Water Inspectorate (DWI) who is the regulator of water quality in England and Wales.

There are also analytical instruments in place that continuously monitor water quality and the treatment processes to ensure the water leaving the site is of the highest quality.

Water quality testing being carried out at a river using a test tube

Sampling at homes

Each year we carry out over 29,000 tests on samples of water collected from customer properties. The customer properties are selected at random, so you may not be expecting us if we call at your home.

However, our team of Water Quality Technicians always wear a uniform, carry identification and will offer a letter explaining our visit, which helps us beat bogus callers.

If we collect a sample from your home and it meets the relevant drinking water standards, you won’t hear from us, unless you have requested a copy of the test results. Very occasionally (less than 0.1% of the time) a result may identify a concern with your water quality. In these instances, we will contact you to investigate further.

Water quality testing being carried out at a home

Check the water in your area

All the results of the regulatory samples collected from our treatment works and customer properties are available to view. Recent results of samples taken in your area can be accessed by entering your postcode. This allows you keep track of your water quality and provides other useful information, like the hardness of your water supply.

Check your water quality