Water company · 2025
Hafren Dyfrdwy's sewage record
943 discharges from 45 monitored storm overflows in 2025, for 6,778 hours in total. These are the Environment Agency's published figures.
943discharges
6,778hours
1monitors working under 90% of the year
The ten worst overflows
| Overflow | Into | Constituency | Discharges | Hours |
|---|---|---|---|---|
| Llanwddyn Wastewater Treatment Works | Vrynwy - Lake Vrynwy to Conf Afon Cownwy | Montgomeryshire and Glyndŵr | 90 | 1,736 |
| Pen-Y-Bont-Fawr Wastewater Treatment Works | Afon Tanat - Conf Hirnant to Conf Afon Rhaeadr | Montgomeryshire and Glyndŵr | 69 | 627 |
| Caersws Wastewater Treatment Works | Severn - Conf Afon Dulas to Conf R Camlad | Montgomeryshire and Glyndŵr | 56 | 615 |
| Montgomery Waste Water Treatment Works | Camlad - Conf Caebitra Bk to Conf R Severn | Montgomeryshire and Glyndŵr | 46 | 449 |
| Caersws Tps | Severn - Conf Afon Dulas to Conf R Camlad | Montgomeryshire and Glyndŵr | 44 | 57 |
| Carno (STW) | Afon Carno - Conf Afon Cwm-Llwyd to Conf R Severn | Montgomeryshire and Glyndŵr | 44 | 191 |
| Trewern Wastewater Treatment Works | Pwll Trewern - Source to Conf R Severn | Montgomeryshire and Glyndŵr | 43 | 582 |
| Guilsfield Wastewater Treatment Works | Guilsfield Bk - Source to Conf Nant Rhyd-Y-Moch | Montgomeryshire and Glyndŵr | 42 | 47 |
| Llanfyllin Wastewater Treatment Works | Afon Cain - Conf Nant Fyllon to Conf the Brogan | Montgomeryshire and Glyndŵr | 41 | 387 |
| Llanidloes - Longbridge South 2 (CSO) | Severn - Conf Afon Dulas to Conf R Camlad | Montgomeryshire and Glyndŵr | 41 | 0 |
The constituencies it affects most
- Montgomeryshire and Glyndŵr — 903 discharges from 41 overflows
- Brecon, Radnor and Cwm Tawe — 40 discharges from 4 overflows
If you are a Hafren Dyfrdwy customer, you cannot switch supplier, but you can claim compensation when they miss a legal standard. What you are owed →
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