Relocating Guildford sewage treatment works
August 2023 update
Guildford sewage treatment works (STW) is currently located on land allocated as part of the Slyfield Area Regeneration Project (SARP) allocated in Guildford Borough Local Plan, which will include the new Weyside Urban Village. We’ve agreed to relocate our STW so this plan can be developed.
The mixed-use regeneration project will include thousands of new homes, new community facilities and 6,500m² of commercial space to improve the local area.
Guildford Borough Council is funding the relocation project, and we’re working closely together to ensure a smooth overlap on both our projects.
We are pleased to say that we are ready to start construction and have been working with Surrey County Council to discharge planning conditions.
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How we’ll build our new STW
Our relocation project has three key elements and will be done in phases:
- A new STW located to the north-east of the existing Slyfield Industrial Estate in Guildford to replace the existing Guildford STW
- New effluent and stormwater outfall pipes to the River Wey, to the northeast of the new STW
- A new gravity transfer tunnel, running from the existing inlet pumping station to the new STW, to transfer incoming wastewater from existing sewers to the new STW
Phase 1: Ground improvement (early August 2023 to Spring 2024)
We'll start by improving the ground at the old landfill site at Slyfield Industrial Estate, which will involve compaction to stabilise it. We'll then drive concrete piles into the ground to help support the structures that are going to be built. You may hear this and see a slight increase of traffic due to deliveries.
Phase 2: Civil engineering (Autumn 2023 to Summer 2025)
This will involve laying pipes underground and building concrete structures on-site from raw materials, like steel and concrete, and receiving timber deliveries. Where we can, we'll use pre-cast concrete panels which are built off-site and then assembled on-site, which will make it quicker, safer and involve fewer delivers and create less noise.
Phase 3: Mechanical and electrical engineering (Summer 2024 to Autumn 2025)
We'll be receiving and installing various mechanical and electrical equipment at this phase. We're expecting there will be minimal disturbance for our neighbours.
Phase 4: Commissioning (Winter 2025/26 to Autumn 2026)
This phase is when the new STW will start to become operational and the existing STW will be taken out of service. There will be minimal disturbance for our neighbours.
Transfer tunnel (August 2023 to Summer 2024)
For us to take wastewater from the existing sewers to the new STW, we'll be constructing a new transfer tunnel. This involves sinking a series of deep shafts below ground to allow us to build a tunnel and connect the existing sewage pipes.
The sinking of the shafts will be carried out during our normal working hours. However, due to the nature of the activity, the underground tunnelling will take place Monday to Saturday, 24 hours a day for short periods. There will be no construction traffic outside of the normal working hours and we intend to minimise disturbance for our neighbours during these works. We'll give you advanced notice if we think you may be affected.
Throughout the duration of our works, we'll be constantly monitoring noise, lighting, vibration, odour, dust and traffic in and around site and will undertake measures to keep these at a minimum.
Key aspects of the project
- Our solution replaces the current site with capacity for treatment of wastewater from a population of at least 120,000
- The site will have space for future expansion in line with modelled growth and the impact of climate change
- Our remediation strategy has been approved by the planning authority and stakeholders
- Our proposal will result in 10% net gain in biodiversity value
- We’re minimising the long term visual impacts of the site by improving and supplementing the tree’s which screen the site from the north
- We’re using the latest odour control methods to minimise any potential impacts on our neighbours
- Our new discharge location will not impact the flooding potential in the River Wey and we’re providing increased storm capacity
- Our work will not impact the nearby allotments and 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 and construction traffic will avoid peak hours where possible
Get in touch
If you have any questions or concerns about the relocation works, please get in touch with us by calling 0800 316 9800, selecting option 1 and quoting reference BB975351.
If you're a business customer, please contact your retailer for additional information relating to our works.