Only three prosecutions by water companies in England and Wales for inadequate drinking water supplies

The drinking water regulator for England and Wales has only brought three prosecutions against water companies for supplying poor quality water since 2021, despite 362 cases where water was deemed unfit for human consumption.

Citizens or companies have periodically informed the Drinking Water Inspectorate about water that is not safe for human consumption. In those cases, the DWI can issue an issue legal instruments which require companies to take a package of measures.

The problems range from old pipes causing discolored water to a deteriorating water treatment process. Improvement measures range from replacing pipes to rebuilding water treatment plants.

Figures show that only a small proportion of these legal instruments have led to prosecution. Water companies are legally obliged to provide their customers with safe drinking water.

Since 2021, the DWI has issued three prosecutions: against Southern Water and South West Water in 2022 and against Wessex Water in 2023. It also issued two warnings: against Thames and Southern Water in 2023.

Southern’s prosecution involved water contaminated with sodium hypochlorite, which resulted in drinking water containing chlorate above the World Health Organization’s recommended guidelines. The company was fined £16,000 and ordered to pay a victim surcharge of £170.

South West Water was fined £233,333 and ordered to pay a victim surcharge of £170 for supplying water unfit for human consumption. It was brown and had a strange smell, and the company responded at the time telling customers to add a slice of lemon to remedy the taste.

Similarly, Wessex Water was prosecuted for supplying water that was unfit for human consumption due to its appearance and taste. It was fined £280,000 and ordered to pay a victim surcharge of £190.

The DWI can prosecute if there is evidence that a criminal offense has been committed, such as supplying water unfit for human consumption, if the company cannot defend that it has taken all reasonable steps and exercised all due care, and if such prosecution is deemed to be in the public interest.

Ahead of the general election, the Liberal Democrats have announced plans for ‘blue flag’ rivers and if elected, the party said it would set legally binding targets to prevent the dumping of sewage at those sites. Blue flag rivers would also give special protected status to swimmers and wildlife.

The Lib Dems also pledged to protect coastal marine wildlife, expanding the Blue Belt of Marine Protected Areas to at least 50% of UK territorial waters by 2030.

The Lib Dems also plan to abolish Ofwat, the water regulator for England and Wales, and introduce one with greater powers. The party also wants to ban bonuses for water company executives.

Last month, unsafe drinking water led to more than 100 cases of cryptosporidium in Brixham, Devon. About 17,000 households and businesses were told by South West Water not to use tap water for drinking without boiling and cooling it first after the parasitic disease was discovered in the supply. People have also fallen ill in Beckenham, south-east London, prompting Thames Water to test the supply for a possible cause.

The Guardian understands that Labor is also considering adding a review of the regulators to its manifesto.

Lib Dem environment spokesman Tim Farron said: “It is a national scandal that drinking water is being polluted by profitable companies (who) show complete disregard for public health and the environment.

“Toothless regulators and failed conservative ministers let water companies get away with this. A slap on the wrist for contaminated water is not enough. This shows what a farce the regulations are.

“The Liberal Democrat’s bold plan to introduce a new water regulator, ban bonuses and reform water companies will crack down on this scandal. Under this Conservative government, water companies’ bonuses and profits have soared, while water supplies have suffered, with sewage destroying beaches and lakes.”

The Drinking Water Inspectorate did not want to comment.