A66 Rider Sewer CSO
Storm overflow operated by Northumbrian Water. The source names Old River Tees as the receiving water.
- 4
- Spills in 2025
- 2.7
- Recorded hours
- 97%
- Monitor operation
- 2
- Years listed
Checking the latest monitor report…
How it compares in 2025
A66 Rider Sewer CSO recorded 4 spills in 2025. That is more than 30% of the 14,239 overflows in England with a reported figure, and ranks 9,334th nationally. Among Northumbrian Water overflows it ranks 1,017th of 1,559; the median Northumbrian Water overflow recorded 11 spills. On the Tees waterbody it ranks 34th of 40.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 4 | 2.7 |
| England | 9,334th of 14,239 | 11 | 22.3 |
| Northumbrian Water | 1,017th of 1,559 | 11 | 15.6 |
| Tees | 34th of 40 | 17.5 | 36.6 |
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 | 4 | 2.7 hours | 97% | Official data |
| 2024 | 3 | 1 hours | 87.9%Low coverage | 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 overflow on the sewer network
- Permit
- 254/0937
- Activity reference
- 1
- Grid reference
- NZ4678718620
- Waterbody ID
- GB510302509900Official 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 “SO on sewer network”: storm overflow on the sewer network. The return places this overflow on the sewer network.
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 1.3 km north-east of the Thornaby-on-Tees 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
- Old River Tees Pumping StationCurrent status unknown
Northumbrian Water · Old River Tees
- Middlesbrough Road SPSCurrent status unknown
Northumbrian Water · River Tees, North Sea
- Bishop Street North CSOCurrent status unknown
Northumbrian Water · River Tees
- Bishop Street North CSOCurrent status unknown
Northumbrian Water · River Tees
Questions about A66 Rider Sewer CSO
- Who operates A66 Rider Sewer CSO?
- Northumbrian Water is the operator named in the annual record. The permit reference is 254/0937.
- Where does A66 Rider Sewer CSO discharge?
- The source names Old River Tees as the receiving water. This does not show how far a discharge travelled.
- How many times did A66 Rider Sewer CSO spill in 2025?
- The 2025 return records 4 counted spill events and 2.7 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 97% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is A66 Rider Sewer CSO 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 A66 Rider Sewer CSO?
- The annual return lists the asset type as “SO on sewer network”, which means storm overflow on the sewer network. The return places this overflow on the sewer network.
- How does A66 Rider Sewer CSO compare with other overflows?
- A66 Rider Sewer CSO recorded 4 spills in 2025. That is more than 30% of the 14,239 overflows in England with a reported figure, and ranks 9,334th nationally. Among Northumbrian Water overflows it ranks 1,017th of 1,559; the median Northumbrian Water overflow recorded 11 spills. On the Tees waterbody it ranks 34th of 40. 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.