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River Seiont polluted by sewage 666 times in 2025 - lasting 5,454 hours

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Contains OS Data © Crown copyright & database right 2021-2024
© Top of the Poops 2021-2024
Totals for River Seiont in 2025
7 Sites polluted by Dwr Cymru Welsh Water
666 sewage dumps
5,454 h duration
That's 7.58 months. On average 1.8 times a day
Constituencies along River Seiont
Places along River Seiont

Pollution Summary 2025

Here are all the reported sewage overflow totals for River Seiont 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 Seiont Pont Rhythallt Pumping Station 140 1,380 99.9
Dwr Cymru Welsh Water River Seiont CAERNARFON STW 90 1,251 99.8
Dwr Cymru Welsh Water River Seiont PENISARWAUN WWTW FE 161 1,199 99.9
Dwr Cymru Welsh Water River Seiont LLANBERIS WwTW 137 1,196 99.8
Dwr Cymru Welsh Water River Seiont CAERNARFON WWTW INLET PUMP ST 6MM 83 301 99.8
Dwr Cymru Welsh Water River Seiont Peblig Industrial Estate CSO 37 97 98.2
Dwr Cymru Welsh Water River Seiont Caernarfon WWTW Inlet Pump ST 6mm SPS 18 28 99.8

Data Sources & Accuracy

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.

This project is not associated, approved or endorsed by any of the companies whose logos you see here.