Benson Sewage Treatment Works ready to take on more capacity as part of Thames Water’s investment programme

• Benson Sewage Treatment works recently completed a £9.7 million upgrade project. 

• This has increased the sites capacity by 29% which will reduce the need for storm overflows during heavy rainfall and produce a higher quality of effluent. 

• This is part of Thames Water’s plan to upgrade 250 of their wastewater sites to help manage demand due to population growth and climate change.   

Having started work in June 2022, Thames Water has completed a £9.7 million upgrade at the end of 2023 and have increased the sites capacity by 29% from 58 to 75 litres per second. The increase in treatment capacity will greatly reduce the risk of storm overflows during spells of heavy rainfall. The upgrade also includes an additional stage in the treatment process which will help to return a better quality of effluent to the river.    

Recently, Freddie van Mierlo, MP for Henley and Thame, local councillors and Thames 21 were invited to visit the site, showcase the improvements and demonstrate the process of treating wastewater every day. 

Awwab Abbasi, Project Manager at Thames Water said: “We are pleased to have completed our upgrades at Benson sewage treatment works to improve our site for residents, businesses and the environment in the area. As custodians of this important infrastructure, we need to ensure our sites are resilient to the pressures of climate change and population growth so we can continue to provide reliable services to our customers.   

“This upgrade to our network will help protect customers and the health of the rivers and waterways. We believe all discharges are unacceptable and we are committed to seeing healthy and thriving waterways, however we can’t do it alone. While we play an important role in this, we aren’t the sole custodians of river health. We need everyone working together to help our waterways thrive.”  

Freddie van Mierlo MP for Henley and Thame said: “I’m grateful to Thames Water for showing me around Benson Sewage Treatment Works and walking me through the upgrades that have taken place there. I welcome all investment in the constituency to increase capacity to handle sewage and decrease storm discharging. Clearly far more needs to be happening across Henley and Thame, and I will be working actively with partners to achieve that”. 

The upgrade of Benson STW is part of Thames Water’s plans to improve 250 of its wastewater sites to help manage the effects of population growth and climate change. These include nearby sites at Cholsely and Dorchester and others in Oxfordshire including its sites in Witney and Oxford. You can see a list of upgrades here. 

Councillor Andrea Powell for Benson & Crowmarsh Ward, South Oxfordshire District Council said: “It was very interesting and reassuring to see the significant investment made by Thames Water in Benson STW. We know how much local people care about river pollution and the effective treatment of increasing levels of sewage caused by major housing developments in the area.” 

Councillor Sue Cooper for Benson & Crowmarsh Ward, South Oxfordshire District Council said: “Having visited the Benson Sewerage Treatment Works almost 40 years ago it was really interesting to see the extra capacity and level of sophistication. I know our local residents are keen to know that there is sufficient capacity there to cope with all the new housing in our area so it will be good to be able to reassure them.”