Media Queries
Get in touch if you have queries or want to discuss our data.
press [at] top-of-the-poops.org
Please Support Us
We rely on donations to fund our work. Please support us if you can
Polluted by sewage 2,326 hours in 2025 , monitoring offline 2,064 hours , potential overflows 336 hours
What's a potential overflow? If the CSO goes 'Offline' while its Overflowing, we don't know if it stopped overflowing until we get a 'Stop' event.
Your local MP is Alistair Strathern (Labour) - Find out more about their interests, donors, and voting at They Work For You
Thank you so much to everyone who contributed to the site in 2025 to keep it running. We do rely on
your contributions! Developing and running a website costs real money.
Please consider a one-off or small recurring donation.
| Company | Site Name | Receiving Waterway | Overflow Days | Total Duration (hours) | Offline/Potential Pollution |
|---|---|---|---|---|---|
| Anglian Water | ASHBROOK STW | Ash Brook, River Great Ouse | 28 | 564 h 27m | - |
| Anglian Water | CLIFTON STW | Henlow Brook | 28 | 528 h 31m | - |
| Anglian Water | HITCHIN STW | River Hiz | 29 | 523 h 33m | - |
| Anglian Water | HITCHIN STW | River Hiz | 23 | 514 h 59m | - |
| Thames Water | Whitwell STW | River Mimram | 13 | 92 h 45m | 750 h |
| Anglian Water | CLIFTON STW | Henlow Brook | 3 | 40 h 48m | - |
| Anglian Water | HITCHIN STW | River Hiz | 2 | 13 h 43m | - |
| Anglian Water | ASHBROOK STW | Ash Brook, River Great Ouse | 3 | 12 h 45m | 336 h |
| Anglian Water | STOTFOLD-BROOK END SP | Tingewick Brook | 1 | 9 h 45m | - |
| Anglian Water | POPPYHILL STW | River Ivel | 3 | 9 h 26m | 1,314 h |
| Anglian Water | POPPYHILL STW | River Ivel | 1 | 6 h 14m | - |
| Anglian Water | HITCHIN STW | River Hiz | 4 | 5 h 5m | - |
| Anglian Water | STOTFOLD-BROOK END SP | Tingewick Brook | 2 | 1 h 54m | - |
| Anglian Water | HITCHIN - GOSMORE SP | Purwell | 1 | 1 h 21m | - |
| Anglian Water | PIRTON TPS | River Hiz | 1 | 1 h 15m | - |
| Anglian Water | POPPYHILL STW | River Ivel | 0 | 0 h | - |
| Thames Water | Whitwell STW | River Mimram | 0 | 0 h | - |
| Anglian Water | PIRTON TPS | River Hiz | 0 | 0 h | - |
| Anglian Water | POPPYHILL STW | River Ivel | 0 | 0 h | - |
| Anglian Water | HITCHIN-BANCROFT REC SSO | River Hiz | 0 | 0 h | - |
| Anglian Water | HITCHIN - GOSMORE SP | Purwell | 0 | 0 h | - |
EDM (Event Duration Monitoring) data and Consented Discharges to Controlled Waters with Conditions from Environment Agency & Data Map Wales, and Scottish Water
Experimental derived data from Thames Water API, Some data may be missing or inaccurate. Live sewage data from Stream Water API
Uses Environment Agency rainfall data from the real-time data API (Beta) - Rainfall data is delayed by up to two days.
This website is intended to provide an accurate representation of the Environment Agency data. The data is hard to use, and thus some errors may have been made. If you find something that is incorrect, please raise an issue at the GitHub issues page and we'll endeavour to fix it quickly.
This project is not associated, approved or endorsed by any of the companies whose logos you see here.
Get in touch if you have queries or want to discuss our data.
press [at] top-of-the-poops.org