Wales is home to the worst sewage-polluted waters, data reveals
THREE constituencies in Wales have been exposed to having the most sewage overflows in 2024.
Grassroots environmental charity, Surfers Against Sewage, released their annual analysis of recorded sewage pollution across England and Wales, ‘Top of the Poops’.
Out of 537 recorded constituencies, Ceredigion Preseli, Caerfyrddin and Dwyfor Meirionnydd were ranked the top three worst affected areas.
Sewage pollution includes everything we flush down the toilet, or wash down the drain, that ends up being released into the environment. It then contaminates water sources and spreads bacteria.
The worst areas for sewage pollution
- Ceredigion Preseli
- Sewage spills: 8,252
- Total pollution time: 94,836 hours (nearly 11 years).
- Main affected waterways: River Teifi, River Taff, Western Cleddau.
2. Caerfyrddin (Carmarthenshire)
- This constituency includes Brecon, Carmarthen, Llanelli, Llansteffan, Ammanford.
- It had 9,821 sewage spills last year.
- Sewage spilled 27 times per day on average.
- 88,840 hours of total pollution time.
- Key waterways affected: River Taifi, River Taf, River Gwili.
3. Dwyfor Meirionnydd
- This constituency, covering Abersoch, Criccieth, Pwllheli and Barnmouth, had the most sewage spills across England and Wales with 10,579.
- Total pollution time: 88,682 hours (over ten years).
- Sewage spilled 29 times a day on average.
- One of its worst-hit CSO’s was Nant Brisgyll, which had 361 spills, lasting 3,666 hours.
Two more Welsh constituencies also made it into the top ten of the worst polluted rivers:
- Mid and South Pembrokeshire ranked seventh.
- Brecon, Radnor and Cwm Tawe came in at number ten.
The remaining 32 constituencies of Wales also appeared on the report, ranging from rankings of 1- 410 out of 537 entries.
The capital’s four seats fared better
None of Cardiff’s constituencies featured in the top 100.
Cardiff West, covering Ely, Canton and Pentyrch had the most spills in the city, with 792 dumps.
Cardiff East, covering Splott, Pentwyn and Trowbridge, was the least effected with only 133 dumps and ranking 410th out of 537.
How are rivers polluted?
Most rivers have sewage release valves called Combined Sewage Overflows (CSOs). These are designed to prevent sewage backup during heavy rainfall. But instead, they often mix sewage with rainwater and discharge it into rivers.
According to the campaigners, this bacterium makes us sick, damages rivers and poisons fish and other wildlife.
Over 121 sites were polluted by Dwr Cymru Welsh Water, who manage Wales’s sewer systems
According to Surfers against Sewage, Dwr Cymru Welsh Water was responsible for at least 105,986 of sewage overflows in 2024.
However, Dwr Cymru have said that rainfall levels and geography affect the number of sewage spills.
“The EDM (Event duration monitoring) figures show a direct correlation between rainfall levels and storm overflow activations. Although 2024 was a wet year, it was drier than 2023, and this contributed to a 7% reduction in total hours of stormwater spills in our operating areas,” said a Dwr Cymru spokesperson.
But, in 2024, South Wales saw one of the wettest months on record in February, where Cardiff rained three times its monthly average.
What now?
Surfers against Sewage have demanded an end to sewage discharge into UK bathing waters by 2030.
The company plans to invest £2.5 billion over five years, with £889 million to improve storm overflows. But, they say removing overflows completely would take decades and would be too expensive.
