Almost a quarter of subpar water samples taken from homes across the UK failed water purity tests because of poor plumbing, a national body for water safety has claimed.

Each year, thousands of water samples are tested for bacteria and substances such as pesticides and metals. Results are then published in an annual report by the chief inspector of drinking water.

Responding to findings published in the latest report, national organisation WaterSafe says that the subpar quality of tap water samples taken from homes around the country can be attributed to a number of factors relating to poor household plumbing.

While the majority of samples met the mark in terms of quality, a small number failed in water purity testing, of which 24 per cent did so because of wrongly connected pipework, sub-standard fixtures or poor tap hygiene.

These factors can cause drinking water quality to deteriorate once the fluid reaches private pipes, which in turn could cause contamination, WaterSafe warns.

Julie Spinks, director of WaterSafe, said that many people don’t realise there are various elements that may affect the quality of water, including “lead pipes, poor quality taps and fittings and even wrongly connected appliances, such as dishwashers, washing machines and even toilets”.

The chief inspector of drinking water for England and Wales Marcus Rink said that consumers need to be aware of the risks poses by poor plumbing and fixtures in terms of water quality. He urged the public not to take any chances and always use the services of reputable plumbers.