Yorkshire Water has embarked on a projected £13.5 million scheme to improve the taste and appearance of tap water by ‘flush’ cleaning large sections of its 31,000 kilometre underground pipe network.

The project, which is ongoing, will improve water quality by reducing the presence of natural sediment in water that over time can stick to the inner lining of old Victorian era cast iron pipes.

The deposits, such as iron and manganese, can if disturbed on occasion cause discoloured water to come out of taps.

To help prevent this, the multi-million pound scheme will involve specialist technicians systematically operating valves on water mains in thousands of streets across the region.

David Stevenson, Head of Water Distribution, said:

"Our mission is to provide water to people that is clean and safe to drink. Drinking water quality within Yorkshire is already excellent with 99.95% of around 500,000 water tests we carried out in the last year meeting the stringent standards set by the Drinking Water Inspectorate. However, this project will improve water quality even further."

Yorkshire Water’s 31,000 kilometres of pipework includes sections of cast iron pipes, which over time can corrode and give an orange-brown discolouration. The water company is currently in the process of replacing hundreds of lead pipes in the network with modern plastic ones to ensure it continues to exceed water quality regulations.

Nearly three quarters of tap water in Yorkshire comes from rivers and reservoirs due to the topography of the region. The rest comes from underground aquifers, which are based mainly in Humberside.

Additional improvements to water quality are also being made by undertaking catchment management activity in areas where water is abstracted from reservoirs, rivers and underground aquifers. This involves working with farmers, landowners and other stakeholders to minimise the impact that naturally occurring nutrients have on water courses that requires expensive water treatment processes to remove.