Image description: Water streaming out of a silver tap. Image by Imani on Unsplash.

Drinking water contamination alerts in Britain have surged by almost 300% in just five years, new data has revealed and reported in the Big Issue, with tap water repeatedly polluted by dangerous chemicals.

Between 2020 and October 2025, 379 drinking water notices were issued across the UK, figures obtained from the Drinking Water Inspectorate show.

The number of notices has climbed from 34 in 2020 to a peak of 131 in 2024, an increase of 285%. Up to October 2025, 93 notices were issued – more than were recorded in 2022 and 2023 combined.

Notices are issued when water quality is compromised or at risk and can require boil notices or supply restrictions. They cover a range of contaminants, including nitrates, PFAS “forever chemicals”, microbial pollution such as E. coli and coliform bacteria. They also include cryptosporidium, a parasite that can cause diarrhoea, vomiting and stomach cramps.

South East Water issued the highest number of notices over the five-year period, with 51 alerts affecting parts of Kent, Surrey and West Sussex.

Read the full report in the Big Issue.