£9.7m project to reduce discharges into Wharfe underway in Addingham

Yorkshire Water has begun a £9.7m investment at Addingham sewage pumping station (SPS) and Low Mill Lane combined storm overflow (CSO) to reduce discharges into the Wharfe, as it continues its commitment to improving bathing water. 

Contractor Morrisons Water Services will be constructing a 3,800m3 underground storage tank, 12.5m diameter which will hold up to 3.8 million litres of wastewater during periods of heavy rainfall, in fields off Ilkley Road. 

The storage tank will hold the rainfall and wastewater flows from the combined sewer until the weather event has passed and the wastewater can be returned to the network for treatment as usual at Ilkley wastewater treatment works.  

The work is part of efforts to reduce discharges from each storm overflow within 5km upstream of the bathing water in Ilkley to one discharge to the river Wharfe per bathing water season (May-September) and no more than ten discharges per year on average – ahead of the Government’s 2035 target. 

Work at Addingham is expected to complete in March 2026. Further investment will take place at Bridge Lane storm overflow and Ilkley Middleton sewage pumping station in the coming months, all of which are also expected to be completed by March 2026. 

Dominic Cunney, project manager at Yorkshire Water, said: “Recent years have seen significant investment in our networks in Ilkley to improve water quality. We are now turning our attention to the storm overflows upstream of the existing bathing water. Over the next 12 months we will be investing tens of millions to reduce discharges dramatically at Addingham, Low Mill Lane, Bridge Lane and Middleton, which will help to improve water quality in the Wharfe. 

“While our investment will reduce our impact on water quality in the Wharfe, it is important that other sources of pollution, such as agriculture, industry and highways drainage are investigated by the appropriate partners and their impacts on the river reduced if bathing water classifications are to be improved.” 

The £9.7m investment at Addingham follows: 

• £60m upgrade to Ilkley wastewater treatment works, which is currently underway
• A new £15m sewer under the A65 to reduce discharges to the Wharfe  
• An extension of the tunnel to reduce discharges from Rivadale storm overflow to one per year per bathing water season in 2026, alongside upgrades to Rivadale CSO
• The addition of UV irradiation treatment at the Draughton, Grassington and Beamsley wastewater treatment works to improve water quality  
• A £1.4m investment at Ben Rhydding wastewater treatment works and Wyvil Crescent storm overflow to further reduce discharges to the Wharfe