Independent councillors have called for a public inquiry over pollution concerns at a quarry in Ynysddu.

Ty Llwyd quarry is believed to contain highly carcinogenic polychlorinated biphenyls (PCBs) – a group of manmade chenicals widely used in the manufacture of electrinic components.

It is thought the PCBs were dumped there by chemical firm Monsanto from its Newport factory decades ago.

The quarry is one of a number of suspected Monsanto dump sites across south Wales. Brofiscin Quarry, in Groesfaen, Rhondda Cynon Taf is the only one designated as contaminated land at the moment – and campaigners want Ty Llwyd to have the same status.

Residents of Ynysddu and its councillors have described a “toxic smell” coming from the council-owned quarry and the nearby community woodlands, where children can be found playing.

A notice of motion has been submitted to Caerphilly County Borough Council asking for support for a public inquiry. It is signed by both Independent Ynysddu councillors – Cllr Janine Reed and Cllr Jan Jones – and Blackwood councillor Kevin Etheridge.

The motion questions whether the system of managing the quarry is “fit for purpose”.

In February, 2022 “historic pollution concerns” at the quarry, which runs past houses at Caerllwyn Terrace and Pontgam Terrace on its way to the Sirhowy river, were raised to the Welsh Government by former council leader Philippa Marsden and the chief executive Christina Harrhy.

Independent councillor Reed said the leachate overflows into the Pantyffynnon Woodland and beyond, and could be  running into the two local rivers – the Sirhowy, and Ebbw.

Cllr Reed said: “At the moment it’s a community woodlands and there’s a public footpath which people use to walk their dogs.

“I’m worried sick about people going in to the woodlands but I can’t do anything because the council are currently saying it’s not contaminated.”

Investigations into pollutants at the quarry have taken place. The council and Natural Resources Wales (NRW) are expected to report back to the Welsh Government on whether action is required.

Independent councillor Etheridge, who represents Blackwood but has also been involved in campaigning on this issue, said: “It is essential we put health and safety measures as a priority at the site and a public inquiry is the only way forward.”

A meeting is being held at the council’s Ty Penallta on Monday, March 6 to discuss the quarry. The independent councillors have asked for this to be a public meeting, but this has not been agreed.

NRW said it is still waiting on the results from the samples taken in January this year.

Member of Senedd for Islwyn Rhianon Passmore said she is expecting an update from the Climate Change Minister Julie James on the situation.

She said: “The relevant agencies must now be allowed to conduct their work and be allowed to report back and undertake any work that is required.”

Earlier this month Conservative MS Natasha Asghar, who represents the South Wales East region, raised the issue with the minister Lesley Griffiths in the Senedd.

She said: “Natural Resources Wales confirms it is solely the council’s responsibility to register contaminated land, but Caerphilly CBC maintains that the leachate does not flow from its property. Will you join me in supporting the residents, Minister, and local councillors Jan Jones and Janine Reed, in calling for a public inquiry to be held?”

In her response, Ms Griffiths, the Senedd’s Trefnydd, said she was aware NRW and the council were working together on the issue.