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Caerphilly - Live Sewage

Polluted by sewage 4,273 hours in 2026 so far..

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Contains OS Data © Crown copyright & database right 2021-2024
© Top of the Poops 2021-2024

Which Year?

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✔ means we have live data (𝑥 if not)

View Annual Sewage Data

You're looking at the totals that we have calculated for sewage in Caerphilly so far for 2026. It is an estimate, based on very poor quality live data from the Water Companies. The water companies report their sewage to the Environment Agency every year in April. You can see the last reported year in the other page

What's a potential overflow? If the CSO goes 'Offline' while its Overflowing, we don't know if it stopped overflowing until we get a 'Stop' event.

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Constituencies near Caerphilly

Daily Data

Jan - 1,649 hours
Feb - 2,130 hours
Mar - 409 hours
Apr - 60 hours
May - 24 hours
Jun - 0 hours
Jul - 0 hours
Daily data is experimental and data is not guaranteed to be accurate. Please inform us of any issue, we will fix.
Please note: We don't have rainfall data for Wales. If you know where to source it please let us know!
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Totals so far

Company Site Name Receiving Waterway Overflow Days Total Duration (hours) Offline/Potential Pollution
Dwr Cymru Welsh Water Bedwas Road Storm Overflow Porset Brook 62 809h -
Dwr Cymru Welsh Water Glan-yr-Afon Lane 2 Storm Overflow River Rhymney 52 746h 16m -
Dwr Cymru Welsh Water Pontllanfraith Gelligroes Mill Road Storm Overflow Sirhowy River 55 612h 30m -
Dwr Cymru Welsh Water Cwm Las Storm Overflow River Rhymni 43 589h 25m -
Dwr Cymru Welsh Water Twyn Road Ystrad Mynach Storm Overflow River Rhymni 41 298h 12m -
Dwr Cymru Welsh Water Springfield Estate Storm Overflow River Sirhowy 39 289h 47m -
Dwr Cymru Welsh Water Gelligroes Roundabout A472 Storm Overflow Sirhowy River 36 125h 37m -
Dwr Cymru Welsh Water Oaks End Close Footbridge Storm Overflow Nant Cylla 28 89h 39m -
Dwr Cymru Welsh Water Ford Road Pengam Storm Overflow River Rhymni 25 82h 34m -
Dwr Cymru Welsh Water Pentwyngwyn Road Storm Overflow River Rhymney 16 81h 50m -
Dwr Cymru Welsh Water Ystrad Mynach Bridge Storm Overflow River Rhymney 18 80h 1m -
Dwr Cymru Welsh Water Bryn Siriol Storm Overflow Nant Yr Aber 17 78h 38m -
Dwr Cymru Welsh Water A472 Maesycwmmer Storm Overflow River Rhymni 16 76h 47m -
Dwr Cymru Welsh Water Commercial Street Senghenydd Storm Overflow Nant Cwm-Parc 6 47h 41m -
Dwr Cymru Welsh Water River Terrace Pengham Storm Overflow River Rhymney 12 43h 14m -
Dwr Cymru Welsh Water William Street Tir-y-berth Storm Overflow River Rhymney 15 40h 15m -
Dwr Cymru Welsh Water Caerphilly Bypass Supermarket Storm Overflow Nant Yr Aber 6 37h 51m -
Dwr Cymru Welsh Water Pontllanfraith Tram Road Storm Overflow Sirhowy River 9 29h 26m -
Dwr Cymru Welsh Water Trelyn Lane Storm Overflow River Rhymni 11 29h 13m -
Dwr Cymru Welsh Water Wyllie Halt Storm Overflow Sirhowy River 5 23h 32m -
Dwr Cymru Welsh Water Main Road Maesycwmmer Overflow Rhymney River 4 14h 53m -
Dwr Cymru Welsh Water Pant Glas Industrial Estate Storm Overflow River Rhymney 5 11h 29m -
Dwr Cymru Welsh Water South of Nine Mile Point Road Wattsville Storm Overflow Sirhowy River 9 10h 48m -
Dwr Cymru Welsh Water Windsor Place Storm Overflow Nant Yr Aber 2 5h 49m -
Dwr Cymru Welsh Water Nine Mile Point Storm Overflow River Sirhowy 3 5h 44m -
Dwr Cymru Welsh Water Woodland Place Storm Overflow River Rhymney 6 4h 43m -
Dwr Cymru Welsh Water Graig-Y-Fedw Storm Overflow Nant Yr Aber 3 2h 43m -
Dwr Cymru Welsh Water High Street Gant-y-nant Storm Overflow River Rhymni 2 2h 12m -
Dwr Cymru Welsh Water New Road Roundabout Storm Overflow River Rhymni 1 1h -
Dwr Cymru Welsh Water Coopers Court Storm Overflow River Rhymni 2 0h 58m -
Dwr Cymru Welsh Water William Street Fleur-de-lis Storm Overflow River Rhymney 2 0h 44m -
Dwr Cymru Welsh Water Forge Road Machen Overflow River Rhymni 2 0h 30m -
Dwr Cymru Welsh Water Nantgawr Road Storm Overflow Nant-yr-Aber 2 0h 29m -
Dwr Cymru Welsh Water Islwyn Road Storm Overflow Sirhowy River 1 0h 14m -
Dwr Cymru Welsh Water Glan-y-nant Riverside Path Storm Overflow River Rhymni 0 0h -
Dwr Cymru Welsh Water Church Street Ystrad Mynach Overflow River Rhymni 0 0h -
Dwr Cymru Welsh Water Railway Cottages Storm Overflow Sirhowy River 0 0h -
Dwr Cymru Welsh Water Coedcae Road Abertridwr Storm Overflow Nant Yr Aber 0 0h -
Dwr Cymru Welsh Water Church Street Rear Ystrad Mynnach Storm Overflow Nant Caeach 0 0h -
Dwr Cymru Welsh Water Forge Road Storm Overflow River Rhymni 0 0h -
Dwr Cymru Welsh Water Victoria Road Fleur-De-Lis Storm Overflow River Rhymni 0 0h -
Dwr Cymru Welsh Water Riverside Park Trethomas Storm Overflow River Rhymney 0 0h -
Dwr Cymru Welsh Water Senghenydd Storm Overflow Nant Yr Aber 0 0h -
Dwr Cymru Welsh Water Trelyn Park Storm Overflow River Rhymney 0 0h -
Dwr Cymru Welsh Water Greenway Bedwas Storm Overflow River Rhymni 0 0h -

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.

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Analysing sewage pollution by the Water Industry

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© Openstreetmap contributors, Contains OS data © Crown copyright and database right 2021-2025,
Contains Water UK National Storm Overflow Hub Data CC-BY-SA 4.0 and analysis © 2025 Top-Of-The-Poops

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