BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276)
Storm overflow operated by United Utilities. The source names River Irwell as the receiving water.
- 55
- Spills in 2025
- 620.3
- Recorded hours
- 99.7%
- Monitor operation
- 2
- Years listed
The reported spill count was 33 lower than in 2024. This compares event counts, not discharge volume.
Checking the latest monitor report…
How it compares in 2025
BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276) recorded 55 spills in 2025. That is more than 90% of the 14,239 overflows in England with a reported figure, and ranks 1,343rd nationally. Among United Utilities overflows it ranks 366th of 2,270; the median United Utilities overflow recorded 15 spills. On the Irwell (Croal to Irk) waterbody it ranks 6th of 56.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 55 | 620.3 |
| England | 1,343rd of 14,239 | 11 | 22.3 |
| United Utilities | 366th of 2,270 | 15 | 29.1 |
| Irwell (Croal to Irk) | 6th of 56 | 16 | 28 |
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 | 55 | 620.3 hours | 99.7% | Official data |
| 2024 | 88 | 555 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
- United Utilities
- Outlet type
- Inlet storm overflow at a wastewater treatment works
- Permit
- 016950032
- Activity reference
- A3
- Grid reference
- SD7655004690
- Waterbody ID
- GB112069061451Official 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 1.4 km east of the Kearsley reference point in the ONS built-up areas data.
Area and water pages
- Wardley area →
- Clifton (Salford) area →
- Swinton (Salford) area →
- Whitefield area →
- Pendlebury area →
- Salford area →
- Prestwich area →
- Rhodes area →
- Simister area →
- Worsley area →
- Eccles (Salford) area →
- Radcliffe area →
- Birch area →
- Old Trafford area →
- Walkden area →
- Kearsley area →
- Little Hulton area →
- Farnworth area →
- Little Lever area →
- Astley area →
- Tyldesley area →
- Bury (Bury) area →
- Higher Folds area →
- Urmston area →
- Atherton area →
- Hunger Hill (Bolton) area →
- Chew Moor area →
- Ainsworth area →
- Bolton (Bolton) area →
- Irwell (Croal to Irk) waterbody →
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
- BOLTON WwTWCurrent status unknown
United Utilities · River Irwell
- Clifton House Road (37010) (SAL0145)Current status unknown
United Utilities · River Irwell via S.W.
- Riverside CSOCurrent status unknown
United Utilities · River Irwell
- Manchester Road / Corrie Drive CSO (079DB)Current status unknown
United Utilities · Unity Brook
Questions about BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276)
- Who operates BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276)?
- United Utilities is the operator named in the annual record. The permit reference is 016950032.
- Where does BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276) discharge?
- The source names River Irwell as the receiving water. This does not show how far a discharge travelled.
- How many times did BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276) spill in 2025?
- The 2025 return records 55 counted spill events and 620.3 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 99.7% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276) 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 BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276)?
- 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 BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276) compare with other overflows?
- BOLTON WwTW, United Utilities (016950032 · A3 · UUP00276) recorded 55 spills in 2025. That is more than 90% of the 14,239 overflows in England with a reported figure, and ranks 1,343rd nationally. Among United Utilities overflows it ranks 366th of 2,270; the median United Utilities overflow recorded 15 spills. On the Irwell (Croal to Irk) waterbody it ranks 6th of 56. 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.