Sewage Map

Nun Monkton Common/CSO

Storm overflow operated by Yorkshire Water. The source names Mill Sike as the receiving water.

4
Spills in 2025
2.4
Recorded hours
100%
Monitor operation
6
Years listed

The reported spill count was 4 lower than in 2024. This compares event counts, not discharge volume.

Current status unknown

Checking the latest monitor report…

Open official annual data ↗

How it compares in 2025

Nun Monkton Common/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 Yorkshire Water overflows it ranks 1,573rd of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Ouse from River Ure to River Nidd waterbody it ranks 3rd of 4.

GroupRank by spillsMedian spillsMedian hours
This outlet–42.4
England9,334th of 14,2391122.3
Yorkshire Water1,573rd of 2,1761637.8
Ouse from River Ure to River Nidd3rd of 42445.3

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

6202015202132022320238202442025
From 2020 to 2025, the reported count went from 6 to 4 spills. The highest count was 15 in 2021 and the lowest was 3 in 2022.
YearSpillsDurationMonitor operationSource
202542.4 hours100%Official data
202481.9 hours100%Official data
202331.7 hours100%Official data
202230.6 hours99.9%Official data
20211564.4 hours99.1%Official data
202061.2 hours100%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
Yorkshire Water
Outlet type
Storm overflow on the sewer network
Permit
EPRUP3222XH
Activity reference
A1
Grid reference
SE5082757995
Waterbody ID
GB104027069592Official 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 2 km south of the Newton-on-Ouse 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

Questions about Nun Monkton Common/CSO

Who operates Nun Monkton Common/CSO?
Yorkshire Water is the operator named in the annual record. The permit reference is EPRUP3222XH.
Where does Nun Monkton Common/CSO discharge?
The source names Mill Sike as the receiving water. This does not show how far a discharge travelled.
How many times did Nun Monkton Common/CSO spill in 2025?
The 2025 return records 4 counted spill events and 2.4 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 100% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
Is Nun Monkton Common/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 Nun Monkton Common/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 Nun Monkton Common/CSO compare with other overflows?
Nun Monkton Common/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 Yorkshire Water overflows it ranks 1,573rd of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Ouse from River Ure to River Nidd waterbody it ranks 3rd of 4. 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.