Thormanby/No 2 STW

Storm overflow operated by Yorkshire Water. The source names Unnamed Tributary of Birdforth Beck as the receiving water.

43
Spills in 2025: 92.8
Recorded hours: 100%
Monitor operation: 3
Years listed

The reported spill count was 15 lower than in 2024. This compares event counts, not discharge volume.

Current status unknown

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How it compares in 2025

Thormanby/No 2 STW recorded 43 spills in 2025. That is more than 84% of the 14,239 overflows in England with a reported figure, and ranks 2,156th nationally. Among Yorkshire Water overflows it ranks 406th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Birdforth/Green's Bks Catch (trib of Swale) waterbody it ranks 2nd of 5.

Group	Rank by spills	Median spills	Median hours
This outlet	–	43	92.8
England	2,156th of 14,239	11	22.3
Yorkshire Water	406th of 2,176	16	37.8
Birdforth/Green's Bks Catch (trib of Swale)	2nd of 5	26	137

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

From 2023 to 2025, the reported count went from 71 to 43 spills. The highest count was 71 in 2023 and the lowest was 43 in 2025.

Year	Spills	Duration	Monitor operation	Source
2025	43	92.8 hours	100%	Official data
2024	58	189.3 hours	100%	Official data
2023	71	114.8 hours	99.9%	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: Inlet storm overflow at a wastewater treatment works
Permit: 27/23/0106
Activity reference: A2
Grid reference: SE4898075180
Waterbody ID: GB104027068790Official 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 3 km west of the Husthwaite reference point in the ONS built-up areas data.

Area and water pages

Birdforth/Green's Bks Catch (trib of Swale) 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.

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Other outlet records nearby

Low Ln Hutton Sessay/CSO
Yorkshire Water · Culverted Tributary Birdforth Beck
Current status unknown

Husthwaite/STW
Yorkshire Water · Elphin Beck
Current status unknown
Raskelf/STW
Yorkshire Water · The Kyle
Current status unknown
Helperby/STW
Yorkshire Water · Culverted Tributary of Swale
Current status unknown

Questions about Thormanby/No 2 STW

Who operates Thormanby/No 2 STW?: Yorkshire Water is the operator named in the annual record. The permit reference is 27/23/0106.
Where does Thormanby/No 2 STW discharge?: The source names Unnamed Tributary of Birdforth Beck as the receiving water. This does not show how far a discharge travelled.
How many times did Thormanby/No 2 STW spill in 2025?: The 2025 return records 43 counted spill events and 92.8 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 Thormanby/No 2 STW 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 Thormanby/No 2 STW?: 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 Thormanby/No 2 STW compare with other overflows?: Thormanby/No 2 STW recorded 43 spills in 2025. That is more than 84% of the 14,239 overflows in England with a reported figure, and ranks 2,156th nationally. Among Yorkshire Water overflows it ranks 406th of 2,176; the median Yorkshire Water overflow recorded 16 spills. On the Birdforth/Green's Bks Catch (trib of Swale) waterbody it ranks 2nd 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.