Sandford Orcas STW
Storm overflow operated by Wessex Water. The source names Tributary of River Yeo as the receiving water.
- 31
- Spills in 2025
- 353
- Recorded hours
- 100%
- Monitor operation
- 2
- Years listed
The reported spill count was 10 lower than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Sandford Orcas STW recorded 31 spills in 2025. That is more than 75% of the 14,239 overflows in England with a reported figure, and ranks 3,344th nationally. Among Wessex Water overflows it ranks 277th of 1,332; the median Wessex Water overflow recorded 11 spills. On the Corton Denham Stream waterbody it ranks 2nd of 3.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 31 | 353 |
| England | 3,344th of 14,239 | 11 | 22.3 |
| Wessex Water | 277th of 1,332 | 11 | 18.9 |
| Corton Denham Stream | 2nd of 3 | 31 | 353 |
Rank 1 has the most spills. Equal counts share a rank. Only overflows with a reported count are ranked. Counts do not measure volume, so a higher rank does not mean more sewage.
Annual spill history
| Year | Spills | Duration | Monitor operation | Source |
|---|---|---|---|---|
| 2025 | 31 | 353 hours | 100% | Official data |
| 2024 | 41 | 546.7 hours | 100% | Official data |
A missing figure means the source did not provide a usable value. A zero is shown as zero. Monitor operation below 90% can make comparison less reliable.
Outlet details
- Water company
- Wessex Water
- Outlet type
- Inlet storm overflow at a wastewater treatment works
- Permit
- 102523
- Activity reference
- 2-STORM DISCHARGE AT STW (UNTREATED)
- Grid reference
- ST6181921542
- Waterbody ID
- GB108052015620Official waterbody record ↗
- Location source
- Official annual grid reference
- Location precision
- About 1 metres
- Location note
- Unknown
About the name and type
The annual return lists this asset as “Inlet SO at WwTW”: inlet storm overflow at a wastewater treatment works. The overflow is at the inlet of a treatment works, where wastewater enters the works.
The waterbody link opens the Environment Agency record for the exact ID in the return. It is a source lookup; we do not import its classification.
Where it is
The recorded position is about 2.6 km east of the Marston Magna reference point in the ONS built-up areas data.
Area and water pages
Check the official record
Public access to this outlet is unknown. Do not enter restricted land or use this page as a route guide.
Open official source ↗Other outlet records nearby
- Sandford Orcas SPSCurrent status unknown
Wessex Water · Corton Denham Stream
- Marston Magna Church LaneCurrent status unknown
Wessex Water · River Yeo (S)
- Poyntington Near Hillside Farm Storm TankCurrent status unknown
Wessex Water · River Yeo
- Sherborne Cheap StreetCurrent status unknown
Wessex Water · Tributary of the River Yeo via SWS
Questions about Sandford Orcas STW
- Who operates Sandford Orcas STW?
- Wessex Water is the operator named in the annual record. The permit reference is 102523.
- Where does Sandford Orcas STW discharge?
- The source names Tributary of River Yeo as the receiving water. This does not show how far a discharge travelled.
- How many times did Sandford Orcas STW spill in 2025?
- The 2025 return records 31 counted spill events and 353 hours of recorded discharge. Spills are counted with the 12/24-hour method, so this is not a count of every start signal.
- Can I trust the 2025 figures for this outlet?
- The monitor worked for 100% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Sandford Orcas STW discharging right now?
- This record is linked to a company live feed. The panel above shows the latest report we hold, with its date. That report can be old, and the monitor can be offline, so check the date before relying on it. A report that no discharge is taking place is not a water-quality result.
- How accurate is the map marker?
- The marker comes from the grid reference in the official annual return, which is accurate to about 1 metres. It shows the recorded outlet position, not the extent of any discharge.
- What kind of outlet is Sandford Orcas STW?
- The annual return lists the asset type as “Inlet SO at WwTW”, which means inlet storm overflow at a wastewater treatment works. The overflow is at the inlet of a treatment works, where wastewater enters the works.
- How does Sandford Orcas STW compare with other overflows?
- Sandford Orcas STW recorded 31 spills in 2025. That is more than 75% of the 14,239 overflows in England with a reported figure, and ranks 3,344th nationally. Among Wessex Water overflows it ranks 277th of 1,332; the median Wessex Water overflow recorded 11 spills. On the Corton Denham Stream waterbody it ranks 2nd of 3. Ranks compare counted spill events only. They do not compare volume or harm.
- Does zero spills mean the water was safe?
- No. A zero means the annual return recorded zero counted spill events for this outlet and year. It is not a water-quality test, and pollution can come from other sources.