Water quality in England and Wales is regulated by the Drinking Water Inspectorate (DWI). This body makes sure all water companies supply safe drinking water that meets legal standards and is acceptable to consumers.

Our sampling programme

While we visit our water source and treatment sites everyday to take samples, a huge part of water quality monitoring involves sampling water at around 12,000 homes and businesses every year. Our samplers always wear a uniform and carry identification which helps us beat bogus callers.


If we visit your property to take a sample and it’s ok, you won’t hear from us. The results will be assessed by the DWI and added to our postcode checker data, providing current water quality updates to customers in your area. 99.9% of samples pass the standards, but if we have concerns about your water quality after a visit, we’ll contact you to investigate. 

A detailed report is published yearly, sharing every water company’s sample results and the conclusions of any audits or assessments. This report, and other information on drinking water quality, is available on the DWI’s website.

All water companies have to closely monitor their water before, during and after the treatment process to make sure it meets the stringent water quality standards of the Water Supply (Water Quality) Regulations 2016 (as amended 2018) .

Take a look at these standards - they mean you really can Love Every Drop!

Programmes of work

To make sure we continue to provide you with excellent drinking water, we sometimes have to undertake work at our water treatment sites or when it’s in distribution (for example, installing new treatment techniques or replacing old water mains).

In addition to our day to day work undertaken on our water treatment sites and  distribution, we have agreed programmes of work with the DWI. These include improvement of treatment capabilities or the introduction of treatment processes to water treatment sites or focused maintenance for example in distribution to improve discolouration risk. Further details of our current programmes of work can be found here. 

Water quality documents

Take a look at our latest drinking water quality report and find out how we treat water in different parts of our region.