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Polluted by sewage 196 times in 2025 lasting 984 hours
Monitoring was disabled in some locations, so could be more
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Donate NowHere are all the reported sewage overflow totals for Troedyrhiw and Pentrebach in 2025. Sometimes sewage can be being dumped for months at a time.
Reporting refers to how much of the time the monitoring was active. In this place 1 of the total 6 CSO Combined Sewage Overflow - a device that, when operating, pours combined rainwater & sewage into a waterway locations had reporting enabled for less than half the year. Of these 1 had zero reporting.
| Company | Waterway | Site | Sewage Dumps | Duration (Hours) | Reporting % |
|---|---|---|---|---|---|
| Dwr Cymru Welsh Water | Taff | CSO PONT RHUN MERTHYR TYDFIL | 96 | 628 | 99.9 |
| Dwr Cymru Welsh Water | Pentrebach Brook | Dixs Field CSO, Pentrebach, Merthyr | 81 | 334 | 94.6 |
| Dwr Cymru Welsh Water | River Taff | Troedyrhiw, Yew Street CSO | 16 | 17 | 81.6 |
| Dwr Cymru Welsh Water | River Taff | TROEDYRHIW PS | 3 | 4 | 99.8 |
| Dwr Cymru Welsh Water | River Taff | Phyllis Street CSO, Troedyrhiw | 0 | 0 | 0 |
| Dwr Cymru Welsh Water | River Taff | TRUNK CSO 2A OFF ABERFAN ROAD | 0 | 0 | 100 |
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.
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Get in touch if you have queries or want to discuss our data.
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