Slough treatment works upgrade
We’re making significant investment at Slough STW. This helps the site grow with the community and meets environmental standards. These works form part of our regulatory commitments and will allow us to:
- Increase capacity and treat more wastewater
- Reduce ammonia and improve the quality of water that’s returned to the environment
- Reduce flood and pollution risks along watercourses
- Upgrade existing assets to improve resilience
- Maintain our current effluent discharge to the Roundmoor ditch system
When and where we'll be working
Work began in 2024, with the detailed design phase starting in November 2025. This is expected to complete in summer 2027 and construction will begin. Construction is expected to last until 2029.
These improvements will benefit customers in Slough and neighbouring areas. In particular, water quality will be improved at Roundmoor and Boveney ditches.
How this may affect you
- Resident and business access will be maintained throughout
- Emergency access will always be prioritised
- You may notice some noise and extra vehicle movements. We’ll do our best to minimise this and may install sound barriers where needed
We’ll do all we can to reduce disruption while we work. But we understand your business may sometimes be affected. View our business loss of profits policy.
What we're working on
- Upgrading the existing plant
- Building new treatment tanks
- Putting in new treatment technology
- Building a new below-ground outfall pipeline
Benefits of the project
- Supporting community and business growth
- Reducing ammonia in the final effluent
- Increasing the full treatment capacity
- Improving water quality in the Roundmoor/Boveney ditches
- Reducing flood risk to the local community
Working with the community
- Community and stakeholder consultation
- Engaged with the Environmental Agency to explore options and embed feedback
- Taken feedback on board from community groups including EWWG and Thames21
- Landowner discussions (including Palmer Estate, Dorney Commoners, Eton College and EA)
- Briefing to Local Planning Authorities
Work along the Roundmoor Ditch
We completed a trial study on the receiving watercourses in the Roundmoor Ditch. This helped us understand how to manage flows and water levels.
We worked with local community groups to action findings from the study. This included addressing issues with weed growth and maintenance. We helped to remove weeds which reduced water levels in the Roundmoor.
Get in touch
If you have questions about this work, contact us on 0800 316 9800. Please quote BB975460.
Get extra support
Our Priority Services Register can help provide a little extra support.
Loss of profits
If you feel your business has been affected, view our business loss of profits policy.