Yorkshire Water investing over £35m to improve health of River Ouse

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. 

Delivered by contract partners Mott MacDonald Bentley, the most significant element of the project will reduce the amount of phosphorus present in the wastewater being returned to the river environment after treatment.  

The scheme includes the installation of ferric dosing, polymer dosing and magnetite dosing – all of which work together to remove solids and phosphorous from the wastewater during treatment before it is returned to the river environment.  

The works will reduce the amount of phosphorus entering the river Ouse and enable faster treatment of wastewater flow.  

This part of the scheme is underway and will be completed in spring 2028. When finished, the work will improve a 9km stretch of the Ouse. Naburn is one of Yorkshire Water’s larger treatment sites. 

Lucie Arger, project manager at Yorkshire Water said; “Phosphorous reduction forms a significant part of our investment plans for the next five years - the project at Naburn is one of 85 phosphorous reduction schemes that we will complete by 2030 in a £350m programme. 

“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.” 

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 dissolved from soil, which can be difficult to control. 

While a small amount of phosphorus is harmless and is an essential part of many ecosystems, it can become damaging to human and animal life when unmanaged. 

Phosphorous removal schemes are already underway at Yorkshire Water’s Kirklington and Leyburn wastewater treatment sites. 

The £350 investment scheme follows a £500m investment in phosphorous removal over the previous five-year delivery period, which saw the amount of phosphorous in treated wastewater in Yorkshire decrease by 68%. 

The other elements of the project will upgrade equipment on the site, such as replacement of atmospheric filtering units, centrifuges, and pipework, to improve its overall efficiency.