A 'Brexit problem': fears over safety of tap water after closure of test labs

The safety of tap water in the UK could be at risk because water companies are unable to use products to clean it, industry insiders have said, as all the laboratories that test and certify these chemicals have shut down.

- Helena Horton

Water industry insiders have called this a "Brexit problem" as EU countries are going to share laboratory capacity from 2026, meaning that if the UK was still in the EU, companies would be able to use products which passed tests on the continent.

But UK rules mean products cannot be tested abroad; they have to be tested in the country in a certified lab, of which there are now none. If companies are unable to keep contaminants out of the water supply, it can cause a danger to health.

In May, thousands of people in Devon fell unwell after the cryptosporidium parasite was detected in the supply. Schools and businesses had to temporarily close and it negatively affected the local economy. Some households had to boil their tap water for a month to remove the contaminant.

Under Drinking Water Inspectorate (DWI) rules, every item or chemical that comes into contact with drinking water has to be tested under stringent conditions, under an EU-derived law known as regulation 31.

This ensures these products are safe to use, do not leach dangerous chemicals into the drinking water supply, and do not encourage the growth of dangerous microbes.