Image description: Boats passing over the river Ouse as it passes through York. Image by Karl Moran on Unsplash

Yorkshire Water is investing over £35m across multiple projects at its Naburn wastewater treatment site in North Yorkshire to improve water quality in the river Ouse and upgrade the site.

The scheme will reduce the amount of phosphorus entering the River Ouse, and upon completion in spring 2028, aims to improve a 5.6-mile (9km) stretch of the Ouse.

While phosphorus is harmless to the aquatic environment in small doses, the company says it can become damaging to human and animal life when unmanaged.

Yorkshire Water said phosphorus is a normal part of domestic sewage and is present in shampoos and liquid detergents. It can also wash off agricultural fields after the use of fertilisers and be released from soil, which can be difficult to control. To remove it, Yorkshire Water said it would install ferric dosing, polymer dosing and magnetite dosing,  all of which work together to remove solids and phosphorous from the wastewater during treatment.

Project manager Lucie Arger said: “The health of Yorkshire’s rivers is incredibly important to us and to our customers, and reducing the levels of phosphorous in our treated wastewater is one way in which we can do our bit to improve it.

“We will also be investing significantly over the next five years to reduce the frequency and duration of storm overflow discharges into the Ouse.”

The project at Naburn is one of 85 phosphorous reduction schemes that are set to be completed by 2030 in a £350m programme.