Yorkshire Water has embarked on a projected £13.5 million scheme to improve the taste and appearance of tap water for millions of customers 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 cast iron pipes.

The mineral deposits, such as iron and manganese, can on occasion if disturbed cause discoloured water to comes out of taps. Although this is unlikely to be harmful to health in such small traces, it can affect taste and make water appear cloudy.

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.  This will enable water to be flushed through the pipes at high speed, which stirs up and removes any historic deposits.

David Stevenson, Head of Water Distribution at Yorkshire Water, 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 section of cast iron pipes which are inherited from the Victorian era and lead pipes. The firm is in the process of replacing hundreds of its lead pipes from its network with modern plastic ones to ensure it continues to exceed water quality regulations.

Yorkshire Water, and its service partner RPS, are carrying out the water quality improvements to ensure it continues to meet the high expectation of customers.  Within the last five years, the firm has reduced water quality customer contacts by 14% and aim to reduce these even further within the next two years.

Robert Light, Northern Chair for the Consumer Council for Water, said: “Customer satisfaction with tap water is already very high, but this investment shows Yorkshire Water is committed to keeping it that way. While the number of customers receiving discoloured water is low, it can affect their quality of life. That’s why we welcome this investment.”

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 where water is abstracted from reservoirs, rivers and underground aquifers. This involves the company  working with farmers, landowners and other stakeholders to minimise the impact that naturally occurring nutrients have on water courses as it requires expensive water treatment processes to remove them.