Triennial Report 2017-2019
Drinking water quality in England
This report demonstrates the high quality of drinking water in England. Of the many thousands of samples taken by water companies during 2017 to 2019, 99.95% met the regulatory standards. The majority of substances met the regulatory standards all of the time (100% compliance). Every sample that failed to meet the standards was investigated and actions put in place to protect consumers and prevent recurrence. Lead and nickel had the poorest performance with lead (99.38%) and nickel (99.74%), followed by coliforms (99.78%), odour (99.78%), iron (99.82%), and taste (99.90%).
Since 2010, when legislation was introduced, the quality of private supplies has been improving, but they still lag behind the standards of the public supplies. During 2017 to 2019, the largest supplies met the regulatory standards for 97.60% of the time.
Drinking water quality in Wales
This report demonstrates the high quality of drinking water in Wales. 99.95% of the many thousands of samples taken each year meet with the regulatory standards. Every sample that fails to meet the standards is investigated and actions put in place to protect consumers and prevent recurrence. This report covers the quality of all public supplies in Wales. There are no private supplies in Wales serving more than 5000 consumers, or 1000 cubic metres a day, and smaller private supplies are not included in the report.