Summerhill pumping station, Ilsington
The monitor is reporting and shows no discharge.
The problem here is local, not the works.
This overflow spilled 290 times on days its own treatment works stayed shut — so the works still had capacity. That points upstream, to this branch of the network, rather than to a works too small for its catchment.
How this verdict is reached →Its permit
What the environmental permit sets for this overflow — and where the public record is silent, which is itself the finding.
- Pass-forward flow
- Not published
- Spill frequency limit
- None set
- Monitoring tier
- Not published
- Assessment trigger
- Crossed — over 10 spills/year
Is anyone acting on this?
Nothing on record.
A flagged problem with no active measure against it. That is a gap in the public record.
What you can do about this one
Ask for the data
Under the Environmental Information Regulations, Summerhill pumping station, Ilsington's telemetry, the works' flow-to-full-treatment setting, and any spill investigations are emissions information — they cannot be withheld on commercial-confidentiality grounds. A written request is the fastest lever.
Get it into the next programme
Investigations that will shape the 2030–35 environment programme must complete by this date. Putting this overflow on the record now — to South West Water and the Environment Agency — is what gets it considered.
Put it in the drainage plan
South West Water's draft Drainage & Wastewater Management Plan goes to a twelve-week consultation. A named overflow with evidence behind it is far harder to leave out.
Put this on the national record
This is the fastest way to act on what you have seen. Our petition asks the Government to publish a fix-by date and yearly progress for every storm overflow. At 100,000 signatures it must be considered for debate in Parliament.
The record since 2020
10 dry spills and 290 pre-STW spills since 2020. Pick a year to see its events below.
2020: 101 spills · 53 discharge events
Counted spills — the EA's 12/24-hour block method, the basis of the 10-a-year cap. Published annual return where available, computed the same way for the current year. Two ways to count →
Dry spills, every year
10 dry spills since 2020 · showing up to 12
Spilled before its works
290 events since 2020 · started while Ilsington System stayed shut
Spills by month, 2020
Dry Wet weatherEvery spill in 2020, most recent first
Each event checked against the nearest rain gauge and against the treatment works’ own overflow. Open any row for its evidence dossier.
Excluded from the counts, classification and flags above — too short to weigh against rainfall, and often an operational blip rather than a genuine discharge. Listed here for completeness. How we know.