Summary

More than 50 years since toxic waste was last dumped, Ty Llwyd Quarry continues to leak some of the most harmful chemicals into the surrounding woodland and river.  Despite ample evidence that measures to contain the toxic legacy of Monsanto and other companies are not working, Caerphilly Council have decided the site is not contaminated land. We are seeking to challenge this position and to ensure meaningful action is taken to clean up the site. 

Site history

In February 1970, Ty Llwyd Quarry, located above the River Sirhowy near Caerphilly, received toxic waste from many sources, including Polychlorinated Biphenyls (PCBs) from Monsanto’s manufacturing plant on the banks of the River Usk at Newport. The dumping continued for two years. The Council has confirmed that the waste includes PCBs.

PCBs are a type of Persistent Organic Pollutant (POP) and are known to cause cancer in animals as well as damage to the immune, reproductive, nervous and endocrine systems. POPs and PCBs are known as “forever chemicals” because they do not break down and are very hard to destroy. They bioaccumulate (become more concentrated at each level of the food chain). Consequently, apex predators, such as herons, dolphins, porpoises, orcas, otters and humans are often the worst affected.

Although over the years testing has demonstrated chemicals are leaking from the site, reports acknowledge that it is contaminated land and government bodies have recommended removing the waste, this has not happened to date. 

Instead, endless testing and report writing has resulted in piecemeal measures without any action aimed at addressing the root cause. 

On 31 July 2026, the Council posted an updated to its website stating that the land was not contaminated following the latest round of testing by their consultants, Arcadis. 

This was despite testing carried out by Dr Dave Megson for the BBC as part of a radio podcast: The Last Witness, June 2024 and the TV programme: Buried with Michael Sheen, August 2026 showing PCBs significantly above average UK levels.

Legal claim

With the help of our legal team (Goodenough Ring Solicitors and Alex Goodman KC of Landmark Chambers), we are seeking to challenge this decision. 

We are looking to raise £35,000 to bring our claim in the High Court. The aim will be to do what should have been done at least 30 years ago – ensure the site is safe and the river, woodland and village environment are not harmed.

We are grateful for all your support.