More than half of homeowners in Wales could be putting their drinking water at risk by not using approved plumbers, new research suggests.

A survey by WaterSafe Register found that just 52% of Welsh homeowners say they always use approved professionals for plumbing work in their homes. While that figure is slightly higher than the UK average of 48%, it still means a significant number are relying on unverified tradespeople.

The warning comes despite the fact that drinking water quality across England and Wales remains exceptionally high. According to the Drinking Water Inspectorate, overall compliance reached 99.97% in 2024.

However, experts say problems are increasingly occurring much closer to home. The Inspectorate’s latest report found that more than 31% of water quality incidents happened on consumer premises. These issues are often linked to internal plumbing faults, including poor pipe fittings, cross-connections, lead pipework, and inadequate backflow protection.

Jonathan Samuel, Managing Director of the WaterSafe Register, said choosing a qualified plumber is one of the simplest and most effective ways to safeguard household water.

“Approved plumbers hold recognised qualifications and understand the regulations that keep tap water safe,” he said. “Safe, high-quality plumbing not only protects against contamination but can also prevent costly leaks and repairs.”

He added that using an approved plumber can also save homeowners time, as certain types of work do not need to be reported to water companies if carried out by registered professionals.

The WaterSafe Register is the UK’s largest directory of vetted plumbers and water contractors, backed by regulators and supported by water companies. It allows homeowners to find qualified specialists in their area who comply with strict water safety standards.

With summer approaching and water usage typically increasing, homeowners are being urged to check credentials before commissioning any plumbing work — a simple step that could help protect both their property and the quality of water coming from the tap.