Great Ayton Sewage Treatment Works
Storm overflow operated by Northumbrian Water. The source names River Leven as the receiving water.
- 50
- Spills in 2025
- 532.7
- Recorded hours
- 99.5%
- Monitor operation
- 6
- Years listed
The reported spill count was 17 lower than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Great Ayton Sewage Treatment Works recorded 50 spills in 2025. That is more than 88% of the 14,239 overflows in England with a reported figure, and ranks 1,626th nationally. Among Northumbrian Water overflows it ranks 115th of 1,559; the median Northumbrian Water overflow recorded 11 spills. On the Leven from Source to Tame waterbody it ranks 1st of 9.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 50 | 532.7 |
| England | 1,626th of 14,239 | 11 | 22.3 |
| Northumbrian Water | 115th of 1,559 | 11 | 15.6 |
| Leven from Source to Tame | 1st of 9 | 19 | 100.4 |
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 | 50 | 532.7 hours | 99.5% | Official data |
| 2024 | 67 | 717.5 hours | 100% | Official data |
| 2023 | 77 | 520 hours | 95.4% | Official data |
| 2022 | Unknown | Unknown | 0%Low coverage | Official data |
| 2021 | Unknown | Unknown | 0%Low coverage | Official data |
| 2020 | 62 | 741.6 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
- Northumbrian Water
- Outlet type
- Storm tank at a wastewater treatment works
- Permit
- 25/04/1859
- Activity reference
- A2
- Grid reference
- NZ5469309700
- Waterbody ID
- GB103025071890Official 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 “Storm tank at WwTW”: storm tank at a wastewater treatment works. The overflow comes from storm storage at a treatment 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 1.9 km south-west of the Great Ayton 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
- Grange Mill Combined Sewer OverflowCurrent status unknown
Northumbrian Water · River Leven
- Tanton Road CSOCurrent status unknown
Northumbrian Water · Meadowfield Stell
- Levenside/Manor Close CSOCurrent status unknown
Northumbrian Water · River Leven
- Stokesley SPS No 2 CSOCurrent status unknown
Northumbrian Water · River Leven
Questions about Great Ayton Sewage Treatment Works
- Who operates Great Ayton Sewage Treatment Works?
- Northumbrian Water is the operator named in the annual record. The permit reference is 25/04/1859.
- Where does Great Ayton Sewage Treatment Works discharge?
- The source names River Leven as the receiving water. This does not show how far a discharge travelled.
- How many times did Great Ayton Sewage Treatment Works spill in 2025?
- The 2025 return records 50 counted spill events and 532.7 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 99.5% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Great Ayton Sewage Treatment Works 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 Great Ayton Sewage Treatment Works?
- The annual return lists the asset type as “Storm tank at WwTW”, which means storm tank at a wastewater treatment works. The overflow comes from storm storage at a treatment works.
- How does Great Ayton Sewage Treatment Works compare with other overflows?
- Great Ayton Sewage Treatment Works recorded 50 spills in 2025. That is more than 88% of the 14,239 overflows in England with a reported figure, and ranks 1,626th nationally. Among Northumbrian Water overflows it ranks 115th of 1,559; the median Northumbrian Water overflow recorded 11 spills. On the Leven from Source to Tame waterbody it ranks 1st of 9. 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.