The drinking water regulator for England and Wales has brought only three prosecutions against water companies for providing poor quality water since 2021, despite 362 instances in which water was flagged as being unfit for human consumption.
Periodically, members of the public or companies have informed the Drinking Water Inspectorate about water that has not been not safe for human consumption. In those instances, the DWI can issue legal instruments that require companies to put in place a package of measures.
The problems range from old pipes causing discoloured water to a deteriorating water-treatment process. Improvement measures vary from replacing pipes to rebuilding water-treatment works.
Figures reveal only a tiny fraction of these legal instruments led to a prosecution. Water companies are under a legal obligation to provide safe drinking water to their customers.
Since 2021, the DWI has brought three prosecutions: against Southern Water and South West Water in 2022 and Wessex Water in 2023. It also gave two cautions: against Thames and Southern Water in 2023.
Southern’s prosecution related to water contaminated with sodium hypochlorite that resulted in drinking water containing chlorate above the World Health Organization’s recommended guidelines. The company was fined £16,000 and a victim surcharge of £170.
South West Water was fined £233,333 and a victim surcharge of £170 for providing water unfit for human consumption. It was brown and had a strange odour, and the company responded at the time by telling customers to add a slice of lemon to remedy the taste.
Similarly, Wessex Water was prosecuted for supplying water unfit for human consumption due to its appearance and taste. It was fined £280,000 and a victim surcharge of £190.
The DWI can take prosecutions forward when there is evidence an offence has been committed, such as providing water that is not fit for human consumption, where the company does not have a defence that it took all reasonable steps and exercised all due diligence, and when such a prosecution is regarded as being in the public interest.
In the run-up to 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 sewage dumping in those sites. Blue flag rivers would also give special protected status for swimmers and wildlife.
The Lib Dems also pledged to protect coastal marine wildlife, which would expand the blue belt of marine protected areas to cover at least 50% of British 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 detected in the supply. People have also been falling ill in Beckenham, south-east London, prompting Thames Water to test the supply for a potential cause.
The Guardian understands Labour is also considering adding an overhaul of the regulators to its manifesto.
The Lib Dem environment spokesperson, Tim Farron, said: “It is a national scandal that drinking water is being contaminated by profiteering firms [that] show complete disregard for public health and the environment.
“Toothless regulators and failed Conservative ministers are allowing water firms to 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 bold plan to bring in a new water regulator, ban bonuses and reform water firms will crack down on this scandal. Under this Conservative government, water company bonuses and profits have soared while water supplies have suffered, all while sewage is destroying beaches and lakes.”
The Drinking Water Inspectorate declined to comment.