About TapWater.uk
TapWater.uk is an independent water quality research project. We aggregate data from UK government sources to provide free, postcode-searchable water quality reports for every area in England and Wales.
Our Mission
Water quality data in the UK is public, but it is scattered across multiple government portals, presented in technical formats, and difficult for ordinary households to interpret. Our mission is to change that. We believe everyone should be able to type in their postcode and immediately understand what is in their tap water — without needing a science degree or hours of research.
By bringing together data from the Drinking Water Inspectorate, individual water companies, and the Environment Agency, we provide a single, plain-English view of water quality that is updated regularly and completely free to use.
How It Works
Our reports are built from three complementary data layers:
- Drinking Water Inspectorate (DWI) — the primary source of treated tap water quality data, covering 48 regulated parameters tested at the tap across England and Wales.
- Water company data — postcode-level supply zone information from the approximately 20 licensed water companies, giving us the most granular geographic mapping available.
- Environment Agency monitoring — supplementary environmental water quality data covering rivers, groundwater, and source waters, which provides broader ecological context for your local area.
You can read more about how we combine these sources on our data sources page, and how we calculate quality scores on our methodology page.
What We Are Not
TapWater.uk is an independent research project. We are not affiliated with any water company, government body, or regulator. Nothing on this site constitutes medical or health advice. Our scores and reports are intended to help you understand publicly available data, not to replace professional guidance.
If you have specific concerns about your water supply — such as a discolouration, unusual taste, or odour — please contact your water supplier directly. They are the authoritative source for supply issues and can carry out testing at your property.
Contact
For questions, corrections, or data feedback, email us at hello@tapwater.uk.