Relocating Guildford sewage treatment works
We've agreed to relocate our Guildford sewage treatment works (STW). This is so the development of the new Weyside Urban Village can take place. The move is in agreement with the Guildford Borough Local Plan.
The project will include thousands of new homes and new community facilities. It will also help improve the local area with 6,500m² of commercial space.
Guildford Borough Council is funding the relocation project. We’re working closely together to ensure a smooth overlap on both our projects. Our remediation strategy has been approved by the planning authority and stakeholders.
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Construction update (January 2025)
Construction has been going well since starting this project. In the last year, there was:
- 12,000m3 of concrete poured on site
- 380 precast panels installed
- Well over 400,000 hours worked
The main tunnel drive connecting the old network to the new is now complete. We’ve compacted the site and installed over 7,200 piles which we hope to finish within the upcoming months.
A lot of civil structures are near completion and mechanical installation has started.
The outfall pipework/structure at the River Wey is complete. This will be the route back to the environment for the ‘treated’ water. The new operational welfare building is being built in the north-west corner of the site.
We expect to complete the works in March 2027.
Drone image of Guildford STW
Civil progress photos
Photo taken from the site offices highlighting the coordination between all contractors
Transfer tunnel update
With the main tunnel works complete, we expect the reception shafts to complete by March 2025.
Benefits of the project
- Capacity for treatment of wastewater will be increased for a population of at least 120,000
- The site will have space for future expansion. This will be in line with modelled growth and the impact of climate change
- Our proposal will result in 10% net gain in biodiversity value
- Minimising the long-term visual impacts of the site. We'll do this by improving and supplementing the north trees which screen the site
How we're working to reduce impact
- We’re using the latest odour control methods to minimise any impacts on our neighbours
- Our new discharge location will not impact the flooding potential in the River Wey. We’re providing increased storm capacity
- Work will not impact the nearby allotments. Mitigation will be in place to reduce the impact of noise or light during construction
- There will be no increase in traffic once the site is operational. Construction traffic will avoid peak hours where possible
Tunnel boring machine at its end point after covering 1400m of distance.
Rapid Impact Compaction Rig used to compact the site. This ensures landfill overtime won't cause significant settlement issues.
Piling rigs driving piles into the ground to provide stability to ground structures.
How we'll build our new STW
Our relocation project has three key elements and will be done in four phases:
Phase 1: Ground improvement
This work has started and is due to complete February 2025.
We're installing around 200 auger bored piles across the site during this phase. In total, we'll be installing 7,800 piles.
Phase 2: Civil engineering
This work has started and is due to complete Autumn 2025.
This will involve laying pipes underground, receiving timber deliveries and building concrete structures. These will be built on-site from steel and concrete.
Where we can, we'll use pre-cast concrete panels. They are built off-site and then assembled on-site. This will make it quicker, safer, involve fewer deliveries, and create less noise.
Phase 3: Mechanical and electrical engineering
From Autumn 2024 to Summer 2026.
We'll be receiving and installing various mechanical and electrical equipment. During this phase, there will be minimal disturbance to our neighbours.
Phase 4: Commissioning
Winter 2025/26 to winter 2027.
The new STW will start to become operational and the existing STW will be taken out of service. During this phase, there'll be minimal disturbance to our neighbours.
Get in touch
If you have any questions or concerns, please get in touch. Call us on 0800 316 9800 selecting option 1 and quoting BB00425695.
For business customers, please contact your retailer for additional information.