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Here are all the reported sewage overflow totals for River Ely in 2025. Sometimes sewage can be being dumped for months at a time.
| Company | Waterway | Site | Sewage Dumps | Duration (Hours) | Reporting % |
|---|---|---|---|---|---|
| Dwr Cymru Welsh Water | River Ely | COSLECH STW PETERSTON SUPER ELY | 118 | 1,263 | 99.7 |
| Dwr Cymru Welsh Water | River Ely | ELY VALLEY ROAD CSO, | 113 | 1,118 | 99.8 |
| Dwr Cymru Welsh Water | River Ely | DUFFRYN ISAF SEWAGE TREATMENT WORKS | 61 | 903 | 99.8 |
| Dwr Cymru Welsh Water | River Ely | Lanelay Park - CSO | 83 | 312 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | Whitebridge PS Peterston Super Ely | 29 | 242 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | CSO at Mill Street, Tonyrefail | 51 | 141 | 99.4 |
| Dwr Cymru Welsh Water | River Ely | CSO at Tonyrefail, Waunrhydd Road | 39 | 112 | 98.8 |
| Dwr Cymru Welsh Water | River Ely | Miskin Sewage Pumping Station Miskin | 19 | 92 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | CSO at TRELAI PARK STORM SEWAGE PS | 31 | 81 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | Penarth Road WDPS | 14 | 81 | 99.8 |
| Dwr Cymru Welsh Water | River Ely | PETERSTON SUPER ELY STW CSO MAIN AV | 17 | 62 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | Brynsadler Pumping Station Clun Ely | 10 | 22 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | Penarth Llandough Moors Cardiff CSO, Cardiff | 16 | 16 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | CSO at Tynybryn Road Tonyrefail R-C-T | 9 | 10 | 99.8 |
| Dwr Cymru Welsh Water | River Ely | Danybryn SPS | 9 | 7 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | Cogan Storm Tank Cogan Penarth | 1 | 5 | 100 |
| Dwr Cymru Welsh Water | River Ely | Ely Mill Rd/Muston Rd CSO, Cardiff | 14 | 5 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | CSO at Penrhiwfer Ashdale Rd CSO, rear of No23 | 6 | 4 | 99.8 |
| Dwr Cymru Welsh Water | River Ely | CSO at Cardiff Ely Plymouth Rd No 108 | 8 | 2 | 99.6 |
| Dwr Cymru Welsh Water | River Ely | Tonyrefail, Mill St CSO | 4 | 1 | 100 |
| Dwr Cymru Welsh Water | River Ely | YNYSDDU PUMPING STATION PONTYCLUN | 1 | 0 | 99.6 |
| Dwr Cymru Welsh Water | River Ely | Mill St CSO, Tonyrefail | 1 | 0 | 57.8 |
| Dwr Cymru Welsh Water | River Ely | Fairview SPS | 0 | 0 | 98.7 |
| Dwr Cymru Welsh Water | River Ely | MAES YR FELIN PUMPING STATION | 0 | 0 | 99.9 |
| Dwr Cymru Welsh Water | River Ely | RHYDYNANT PS (ADJ TO 49) PONTYCLUN | 0 | 0 | 99.9 |
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
Annual figures up to and including 2025 come from official water company returns. The 2026 figure is our own estimate, derived continuously from the companies' live data feeds.
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