Stockport WwTW Heaton's Sewer CSO (STOCK)
Storm overflow operated by United Utilities. The source names River Mersey as the receiving water.
- 38
- Spills in 2025
- 106.1
- Recorded hours
- 99.4%
- Monitor operation
- 2
- Years listed
The reported spill count was 38 higher than in 2024. This compares event counts, not discharge volume.
We do not have a live report for this outlet. Its annual spill records are shown below.
How it compares in 2025
Stockport WwTW Heaton's Sewer CSO (STOCK) recorded 38 spills in 2025. That is more than 81% of the 14,239 overflows in England with a reported figure, and ranks 2,593rd nationally. Among United Utilities overflows it ranks 624th of 2,270; the median United Utilities overflow recorded 15 spills. On the Mersey (upstream of Manchester Ship Canal) waterbody it ranks 21st of 51.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 38 | 106.1 |
| England | 2,593rd of 14,239 | 11 | 22.3 |
| United Utilities | 624th of 2,270 | 15 | 29.1 |
| Mersey (upstream of Manchester Ship Canal) | 21st of 51 | 28 | 60 |
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 | 38 | 106.1 hours | 99.4% | Official data |
| 2024 | 0 | 0 hours | 99.3% | 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
- Permit applied for
- Activity reference
- A1
- Grid reference
- SJ8644089690
- Waterbody ID
- GB112069061030Official 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 1.7 km north of the Cheadle (Stockport) reference point in the ONS built-up areas data.
Area and water pages
- Manchester area →
- Droylsden area →
- Audenshaw area →
- Denton (Tameside) area →
- Reddish area →
- Old Trafford area →
- Stretford area →
- Bredbury and Woodley area →
- Stockport area →
- Romiley area →
- Sale area →
- Gatley area →
- Wythenshawe area →
- Cheadle (Stockport) area →
- Marple area →
- Mersey (upstream of Manchester Ship Canal) 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
- STOCKPORT WwTWCurrent status unknown
United Utilities · River Mersey
- STOCKPORT WwTWCurrent status unknown
United Utilities · River Mersey
- Heaton Moor CSOCurrent status unknown
United Utilities · River Mersey
- Junction of High Street /Stockport Rd / Manchester Rd CSOCurrent status unknown
United Utilities · Micker Brook
Questions about Stockport WwTW Heaton's Sewer CSO (STOCK)
- Who operates Stockport WwTW Heaton's Sewer CSO (STOCK)?
- United Utilities is the operator named in the annual record. The permit reference is Permit applied for.
- Where does Stockport WwTW Heaton's Sewer CSO (STOCK) discharge?
- The source names River Mersey as the receiving water. This does not show how far a discharge travelled.
- How many times did Stockport WwTW Heaton's Sewer CSO (STOCK) spill in 2025?
- The 2025 return records 38 counted spill events and 106.1 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 99.4% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Stockport WwTW Heaton's Sewer CSO (STOCK) discharging right now?
- This record is not matched to a company live feed, so we cannot show a current report. Only the annual figures are available for this outlet.
- 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 Stockport WwTW Heaton's Sewer CSO (STOCK)?
- 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 Stockport WwTW Heaton's Sewer CSO (STOCK) compare with other overflows?
- Stockport WwTW Heaton's Sewer CSO (STOCK) recorded 38 spills in 2025. That is more than 81% of the 14,239 overflows in England with a reported figure, and ranks 2,593rd nationally. Among United Utilities overflows it ranks 624th of 2,270; the median United Utilities overflow recorded 15 spills. On the Mersey (upstream of Manchester Ship Canal) waterbody it ranks 21st of 51. 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.