Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087)
Storm overflow operated by Anglian Water. The source names The Slade River as the receiving water.
- 9
- Spills in 2025
- 3.5
- Recorded hours
- 98.7%
- Monitor operation
- 5
- Years listed
The reported spill count was 18 lower than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087) recorded 9 spills in 2025. That is more than 45% of the 14,239 overflows in England with a reported figure, and ranks 7,492nd nationally. Among Anglian Water overflows it ranks 543rd of 1,438; the median Anglian Water overflow recorded 6 spills. On the Slade waterbody it ranks 3rd of 5.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 9 | 3.5 |
| England | 7,492nd of 14,239 | 11 | 22.3 |
| Anglian Water | 543rd of 1,438 | 6 | 13.5 |
| Slade | 3rd of 5 | 9 | 3.8 |
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 | 9 | 3.5 hours | 98.7% | Official data |
| 2024 | 27 | 24.5 hours | 100% | Official data |
| 2023 | 26 | 15.5 hours | 99.7% | Official data |
| 2022 | 17 | 13 hours | 99.9% | Official data |
| 2021 | 13 | 19.3 hours | 99.8% | 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
- Anglian Water
- Outlet type
- Inlet storm overflow at a wastewater treatment works
- Permit
- ASCNF1184
- Activity reference
- A3
- Grid reference
- TL5272038600
- Waterbody ID
- GB105033037580Official 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 1.6 km south-east of the Littlebury 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
- Saffron Walden STWCurrent status unknown
Anglian Water · The Slade River
- Saffron Walden-George Abbey OvCurrent status unknown
Anglian Water · The Slade Tributary of River Cam
- Castle Street/High Street Combined Sewer OverflowCurrent status unknown
Anglian Water · The Slade
- Saffron Walden-Victoria Thx OvCurrent status unknown
Anglian Water · The Slade
Questions about Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087)
- Who operates Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087)?
- Anglian Water is the operator named in the annual record. The permit reference is ASCNF1184.
- Where does Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087) discharge?
- The source names The Slade River as the receiving water. This does not show how far a discharge travelled.
- How many times did Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087) spill in 2025?
- The 2025 return records 9 counted spill events and 3.5 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 98.7% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087) 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 Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087)?
- 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 Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087) compare with other overflows?
- Saffron Walden STW, Anglian Water (ASCNF1184 · A3 · AWS01087) recorded 9 spills in 2025. That is more than 45% of the 14,239 overflows in England with a reported figure, and ranks 7,492nd nationally. Among Anglian Water overflows it ranks 543rd of 1,438; the median Anglian Water overflow recorded 6 spills. On the Slade waterbody it ranks 3rd of 5. 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.