Sewage Map

Dilton Marsh Pen Knapp

Storm overflow operated by Wessex Water. The source names Biss Brook(S) as the receiving water.

1
Spills in 2025
3.1
Recorded hours
99.9%
Monitor operation
4
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…

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How it compares in 2025

Dilton Marsh Pen Knapp recorded 1 spill in 2025. That is more than 15% of the 14,239 overflows in England with a reported figure, and ranks 11,130th nationally. Among Wessex Water overflows it ranks 1,036th of 1,332; the median Wessex Water overflow recorded 11 spills.

GroupRank by spillsMedian spillsMedian hours
This outlet–13.1
England11,130th of 14,2391122.3
Wessex Water1,036th of 1,3321118.9

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

02022120235202412025
From 2022 to 2025, the reported count went from 0 to 1 spills. The highest count was 5 in 2024 and the lowest was 0 in 2022.
YearSpillsDurationMonitor operationSource
202513.1 hours99.9%Official data
2024518.9 hours100%Official data
202312 hours100%Official data
202200 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
Wessex Water
Outlet type
Storm discharge at a pumping station
Permit
103205
Activity reference
1-STORM/EMERGENCY
Grid reference
ST8585049850
Waterbody ID
GB109053021750Official 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 “Storm discharge at pumping station”: storm discharge at a pumping station. The overflow is at a pumping station that moves sewage through the 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 0.6 km east of the Dilton Marsh 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.

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Other outlet records nearby

Questions about Dilton Marsh Pen Knapp

Who operates Dilton Marsh Pen Knapp?
Wessex Water is the operator named in the annual record. The permit reference is 103205.
Where does Dilton Marsh Pen Knapp discharge?
The source names Biss Brook(S) as the receiving water. This does not show how far a discharge travelled.
How many times did Dilton Marsh Pen Knapp spill in 2025?
The 2025 return records 1 counted spill events and 3.1 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 99.9% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
Is Dilton Marsh Pen Knapp 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 Dilton Marsh Pen Knapp?
The annual return lists the asset type as “Storm discharge at pumping station”, which means storm discharge at a pumping station. The overflow is at a pumping station that moves sewage through the network.
How does Dilton Marsh Pen Knapp compare with other overflows?
Dilton Marsh Pen Knapp recorded 1 spill in 2025. That is more than 15% of the 14,239 overflows in England with a reported figure, and ranks 11,130th nationally. Among Wessex Water overflows it ranks 1,036th of 1,332; the median Wessex Water overflow recorded 11 spills. 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.