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Polluted by sewage 519 times in 2025 lasting 3,669 hours
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Donate NowHere are all the reported sewage overflow totals for Ystradgynlais 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 all the declared CSO Combined Sewage Overflow - a device that, when operating, pours combined rainwater & sewage into a waterway s appeared to have monitoring enabled for more than 50% of the year
| Company | Waterway | Site | Sewage Dumps | Duration (Hours) | Reporting % |
|---|---|---|---|---|---|
| Dwr Cymru Welsh Water | Culverted, River Tawe | CSO 4 Opposite Lamb & Flag Cottages | 141 | 1,856 | 98.8 |
| Dwr Cymru Welsh Water | River Tawe | SWN YR AFON CSO, Ystradgynlais | 58 | 348 | 94.8 |
| Dwr Cymru Welsh Water | River Tawe | Rear of Canal Cottage CSO, Abercrave | 39 | 298 | 96.3 |
| Dwr Cymru Welsh Water | River Tawe | CSO at O/S 17 Glantawe Row Ystradgynlais | 74 | 251 | 99.1 |
| Dwr Cymru Welsh Water | River Tawe | SWO.M'HOLE12 CWMTAWE FM PENRHOS | 36 | 244 | 97.7 |
| Dwr Cymru Welsh Water | River Tawe | CSO at MH 92 nr Claypon Bridge, Ystradgynlais | 35 | 214 | 99.4 |
| Dwr Cymru Welsh Water | River Tawe | CSO 12 B4599 Road Bridge | 59 | 166 | 99.8 |
| Dwr Cymru Welsh Water | Nant Gyrlais | CSO 10 Rear Of Waun Gyrlais Penrhos | 39 | 131 | 76.7 |
| Dwr Cymru Welsh Water | River Tawe | CSO at Mason Arms, Ystradgynlais | 24 | 116 | 99.4 |
| Dwr Cymru Welsh Water | River Tawe | Nr Gough Arms MH CSO | 14 | 41 | 96.7 |
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.
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Get in touch if you have queries or want to discuss our data.
press [at] top-of-the-poops.org