According to TapWater.uk's analysis, Cardiff scores 9.5/10 for drinking water quality in 2026. Water is supplied by Dŵr Cymru Welsh Water and has been tested for 23 contaminants across 9 postcode districts.
9.5 / 10
9 areas tested · 0 flagged · UK average 9.0
Yes, Cardiff tap water is safe to drink. Based on 9 areas tested, Cardiff has an average water quality score of 9.5/10 (above the UK average of 9.0/10). No contaminants were found above recommended levels. Water is supplied by Dŵr Cymru Welsh Water. Dŵr Cymru Welsh Water supplies Cardiff from reservoirs in the Brecon Beacons and Taff Fawr valley.
All postcode districts in Cardiff, ranked by water quality score.
| Postcode | Area | Score | Flagged | Supplier |
|---|---|---|---|---|
| CF24 | Cardiff | 9.3 | 0 | Dŵr Cymru Welsh Water |
| CF10 | Cardiff | 9.4 | 0 | Dŵr Cymru Welsh Water |
| CF11 | Cardiff | 9.4 | 0 | Dŵr Cymru Welsh Water |
| CF14 | Cardiff | 9.4 | 0 | Dŵr Cymru Welsh Water |
| CF15 | Cardiff | 9.4 | 0 | Dŵr Cymru Welsh Water |
| CF23 | Cardiff | 9.4 | 0 | Dŵr Cymru Welsh Water |
| CF3 | Cardiff | 9.4 | 0 | Dŵr Cymru Welsh Water |
| CF5 | Cardiff | 9.4 | 0 | Dŵr Cymru Welsh Water |
| CF30 | Cardiff | 10.0 | 0 | Dŵr Cymru Welsh Water |
Taste, chlorine and hardness bother people even where the water passes its tests. These are the three fixes our readers pick most: a jug for drinking water, a shower filter, and a reverse osmosis unit that needs no plumbing. Check your own postcode above to see which one your water needs.
The jug for cleaner drinking water
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Affiliate link: we may earn a commission at no extra cost to you. How recommendations are funded
Yes, Cardiff tap water is generally safe to drink. Across 9 areas tested, the average water quality score is 9.5/10. Dŵr Cymru Welsh Water supplies Cardiff from reservoirs in the Brecon Beacons and Taff Fawr valley.
Yes, you can drink tap water in Cardiff. It is regulated to UK drinking water standards, and across 9 tested areas the average water quality score is 9.5/10. Enter your postcode for the readings in your exact area.
No contaminants were flagged above recommended levels across Cardiff. All tested areas passed on the parameters measured.
Hardness data is not yet available for Cardiff. Enter your postcode for detailed water quality data.
The areas with the best water quality in Cardiff are CF30 (10.0/10), CF10 (9.4/10), CF11 (9.4/10).
Water in Cardiff is supplied by Dŵr Cymru Welsh Water. Dŵr Cymru Welsh Water supplies Cardiff from reservoirs in the Brecon Beacons and Taff Fawr valley.
No PFAS (forever chemicals) have been detected in any of the 9 areas tested in Cardiff.
Free live water quality widget for CF30: paste these two lines anywhere on your page. It stays up to date by itself and credits TapWater.uk automatically.
<div data-tapwater-postcode="CF30"></div>
<script src="https://www.tapwater.uk/widget.js" async></script>Get a detailed water quality report for your exact area in Cardiff.
Based on water quality data from 9 postcode districts in Cardiff. Data from your water company via the Stream Water Data Portal and the Environment Agency. See our methodology for how scores are calculated.