North Hill STW So North Hill

Storm overflow operated by South West Water. The source names River Lynher as the receiving water.

19
Spills in 2025: 99.4
Recorded hours: 98.4%
Monitor operation: 5
Years listed

The reported spill count was 66 lower than in 2024. This compares event counts, not discharge volume.

Current status unknown

Checking the latest monitor report…

How it compares in 2025

North Hill STW So North Hill recorded 19 spills in 2025. That is more than 62% of the 14,239 overflows in England with a reported figure, and ranks 5,217th nationally. Among South West Water overflows it ranks 709th of 1,357; the median South West Water overflow recorded 21 spills. On the Lower River Lynher waterbody it ranks 7th of 9.

Group	Rank by spills	Median spills	Median hours
This outlet	–	19	99.4
England	5,217th of 14,239	11	22.3
South West Water	709th of 1,357	21	39.4
Lower River Lynher	7th of 9	33	452.6

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

From 2021 to 2025, the reported count went from 132 to 19 spills. The highest count was 136 in 2022 and the lowest was 19 in 2025. The monitor worked for less than 90% of 2022, so that count may be low.Amber bars mark years when the monitor worked for less than 90% of the year.

Year	Spills	Duration	Monitor operation	Source
2025	19	99.4 hours	98.4%	Official data
2024	85	340.4 hours	100%	Official data
2023	82	328.8 hours	100%	Official data
2022	136	360.1 hours	11%Low coverage	Official data
2021	132	349 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: South West Water
Outlet type: Inlet storm overflow at a wastewater treatment works
Permit: NRA-SW-6621
Activity reference: A2
Grid reference: SX27037631
Waterbody ID: GB108047007670Official waterbody record ↗
Location source: Official annual grid reference
Location precision: About 10 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 4.3 km south of the Lewannick reference point in the ONS built-up areas data.

Area and water pages

Lower River Lynher 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

Bathpool STW So Bathpool
South West Water · River Lyner (S)
Current status unknown

Rilla Mill STW So Rilla Mill
South West Water · (S) River Lynher
Current status unknown
Upton Cross CSO Rilla Mill
South West Water · Tributary of River Lyner
Current status unknown
Minions CSO Minions
South West Water · East Looe River (S)
Current status unknown

Questions about North Hill STW So North Hill

Who operates North Hill STW So North Hill?: South West Water is the operator named in the annual record. The permit reference is NRA-SW-6621.
Where does North Hill STW So North Hill discharge?: The source names River Lynher as the receiving water. This does not show how far a discharge travelled.
How many times did North Hill STW So North Hill spill in 2025?: The 2025 return records 19 counted spill events and 99.4 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 98.4% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
Is North Hill STW So North Hill 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 10 metres. It shows the recorded outlet position, not the extent of any discharge.
What kind of outlet is North Hill STW So North Hill?: 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 North Hill STW So North Hill compare with other overflows?: North Hill STW So North Hill recorded 19 spills in 2025. That is more than 62% of the 14,239 overflows in England with a reported figure, and ranks 5,217th nationally. Among South West Water overflows it ranks 709th of 1,357; the median South West Water overflow recorded 21 spills. On the Lower River Lynher waterbody it ranks 7th of 9. 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.