The situation
Across the South West our sewerage system is showing its age and needs upgrading. This is especially true of the sewer running from the pumping station in Penryn. Following a number of bursts in the past few years, it's reached the end of its working life and needs replacing.
Recent upgrades to the pumping station and this replacement of the main will add resilience to the network and reduce the risk of pollution.
Works taking place
Before starting the main works, we’ll drill trial holes. These help us understand the soil, rock, and groundwater conditions at the locations.
For most of this project, we’ll be using open-cut excavation – which means we’ll dig a trench down to the pipe, cut the pipe out, and replace that section. This type of work is noisy and produces dust. We’ll be using pneumatic drills, diggers, and other noisy equipment to complete the replacement.
In some sections, we’ll use pipe lining, which is when a repair happens inside the pipe itself. Unfortunately, due to the fragility of the sewer, we are unable to use this technique for the full length of the pipe.
| Date | Activity |
|---|---|
| Monday 16 February to Thursday 26 February 2026 | Investigation – trial pits |
| Monday 2 March to Friday 27 March 2026 | Pipework construction |
| Monday 9 March to Friday 27 March 2026 | Lining pipework |
| Tuesday 31 March 2026 | Works completion date |
Completed works
New mains installation: March 2024
Stage 1: Commercial Road to Falmouth Road
New mains installation, completed between January and February 2024.
Stage 2: Eastwood Road at junction of Falmouth Road
Update: July 2025
We were due to finish the work on Commercial Road by Wednesday 23 July, which was the earliest date permitted by Cornwall Highways because of other utility works in the area. The work required temporarily shutting down the pumping station. At the time, the weather forecast predicted prolonged rainfall, which meant closing the pumping station would have posed a risk to the environment.
1. Preparation
- Set up traffic management and safety barriers
- Survey the site and mark up the existing services – we do not want to damage other utilities!
2. Digging down
We excavate down to the correct depth, creating a trench for the new pipe. We use diggers for most of the work, but areas around other services have to be dug out by hand to avoid damage.
3. Installing the pipe
- The new pipe is installed on suitable bedding to protect it
- It is then pressure tested to ensure it doesn't leak
4. Introduce flow into sewer
The new pipe is connected into the network and the sewer is brought into service.
5. Restore the working area
We backfill the trench with stone, restore the road surface and repaint any road markings before clearing the site and then the road is opened again as normal.