Falmouth Stormwater Overflow Improvement Scheme
We're working fast to reduce spills in Falmouth
Falmouth's beach at Gyllyngvase has enjoyed Good bathing water for many years now.
But we know that sometimes the sewer system is struggling to cope. Our investigations tell us that this is for a number of reasons including population growth in the area, groundwater entering the sewers, and the age of some of our assets.
We're on a mission to reduce the impact the town's sewerage system is having on the environment, including in the estuary waters.
What we're doing
This scheme has four major elements to deliver before our government-imposed deadline of 30 March 2028.
1. Surface water separation
Combined sewers take both foul sewage from homes and businesses, as well as surface water from roads, to the treatment works.
Being rainwater, surface water doesn't need much treatment before being released back into rivers. Sending it to the treatment works not only wastes energy and money in transporting and treating it, but also risks overloading our pump stations and storm tanks.
By seperating sewers (building one to hold the foul flows and one to hold surface water) we can reduce the flows inside our sewers and reduce the risk of storm overflows. The surface water is released into rivers after going through an oil interceptor.
2. Infiltration
Infiltration is when surface water or groundwater enters our sewers in places it's not meant to (e.g. through manhole covers).
This means that a lot more wastewater enters the sewers and increases the risk of activating our storm overflows.
To stop infiltration we'll be lining, repairing and replacing our pipes and manhole covers in hotspot areas. We call this rehabilitation work.
3. Storm storage
Storm water is the number one cause of storm overflows. The huge rainfalls we're experiencing as climate change takes hold are overwhelming our sewers, meaning our storm tanks fill up faster and start overflowing before our pumps have chance to reduce the volume inside them.
We're hoping that our work to reduce infiltration will help reduce the amount of storm water entering our sewers.
But, we're also making sure there's enough storage to hold it all. That's why we're looking into building brand new storm storage near Queen Mary Gardens and The Moor, and we're investigating other potential areas.
4. Our treatment works
By upgrading our treatment works we can reduce the amount of time wastewater stays in our system. We're looking into ways to increase the volume of wastewater that can be treated at any time. A solution will be designed based on the results of our investigations.
When we're doing it
We're carrying out a lot of investigating and surveying to find the best solution for Falmouth's sewerage system.
We're still in the designing and developing stage, so we don't have any confirmed dates of when the work is due to start.
However, an estimated delivery programme is below. These dates are subject to change.
| Projects | Estimated dates |
|---|---|
| Infiltration reduction |
CCTV surveys - 2024 First phase - 2025 Second phase - 2026/2027 |
| Increasing storm storage |
Surveys and design - 2024 Construction - 2024-2027 |
| Separating sewers |
Surveys and investigations - 2024 Separation starts - 2025 |
| Upgrading treatment works |
Surveys, investigations and designs - 2026 Upgrades start - 2027 |