Top of the Poops | Place | Ynysybwl | Polluted by Dwr Cymru Welsh Water

It's a Dirty Business

Watch Channel 4's documentary about the state of the water industry, then sign the petition to bring water back to public ownership.

Select Another Place

Place Name

Select the place from the drop-down

✔ means we have live data

Totals for Ynysybwl in 2025

10 Sites polluted by Dwr Cymru Welsh Water

586 sewage dumps

4,785 hours duration

That's 6.65 months. On average 1.6 times a day

Change Over Time

Constituency for Ynysybwl

Nearby Constituencies

Waterways in Ynysybwl

Take Action

Your local MP is Alex Davies-Jones (Labour) - Find out more about their interests, donors, and voting at They Work For You

Share this page, post a message, and tell others about the huge problem of sewage pollution across the UK

We need your support!

Please consider a one-off or small recurring donation. We need your help to keep this site going.

Donate Now

Pollution Summary 2025

Here are all the reported sewage overflow totals for Ynysybwl 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	River Taff	CILFYNYDD STW CILFYNYDD PONTYPRID	112	1,698	97.7
Dwr Cymru Welsh Water	River Taff	CYNON VALLEY STW GLYNCOCH PONTY	64	778	99.9
Dwr Cymru Welsh Water	Nant Clydach	Tank Near Pit CSO Ynysybwl	90	553	89.7
Dwr Cymru Welsh Water	Nant Clydach	GLYN STREET CSO GLYN ST YNYSYBWL	98	521	99.3
Dwr Cymru Welsh Water	River Taff	Cilfynydd STW Cilfynydd Pontypridd Settled Storm	20	329	99.8
Dwr Cymru Welsh Water	Culvert	NEW ROAD SEWERAGE SYSTEM (REDESIGNE	29	327	96.3
Dwr Cymru Welsh Water	Nant Clydach	Old Parish Road CSO, Ynysbwl	83	253	98.3
Dwr Cymru Welsh Water	Nant Clydach	CSO at Clydach Rd, Ynysbwl	47	228	99.3
Dwr Cymru Welsh Water	Nant Clydach	CSO O/S 2 Clydach Terrace, Ynysybwl	34	88	80.2
Dwr Cymru Welsh Water	Nant Cae-Dudwg	End of Park Place CSO, Cilfynydd	9	8	99.7
Dwr Cymru Welsh Water	Nant Cae-Dudwg	PARK PLACE CSO	0	0	99.9

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.

Analysing sewage pollution by the Water Industry

Media Queries

Get in touch if you have queries or want to discuss our data.

press [at] top-of-the-poops.org

Please Support Us

We rely on donations to fund our work. Please support us if you can

Yes! Support TOTP!

© 2020-2025 Top-Of-The-Poops CC-BY-SA 4.0,
© 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

Some data reproduced under Open Government Licence

Please don't scrape these pages - we can maybe share our data with you