In the first article of this series on historic toxic chemical waste in Wales, The National examined the dumping of carcinogenic toxic waste from Newport’s Monsanto factory at two disused quarries in what is now Rhondda Cynon Taf.

The first of these - Brofiscin quarry in the village of Groesfaen near Pontyclun - started leaking in 2003, and attempts to remediate the site led to a waterproof cap being built in 2011.

To all intents and purposes, the story for this quarry ends here, officially anyway. Rainwater can’t add to the breakdown of barrels that are buried there, and theoretically, fresh water is unable to become contaminated by the harmful waste that lies there in rotting barrels.

PART ONE: How toxic waste has been dumped across Wales and never properly cleaned up

PART TWO: The legacy of a Newport site that still discharges toxic chemicals into the Severn

However, its twin site - Maendy quarry - about a mile west of Hawthorn in Pontypridd, on the hills above Church Village and Treforest - has never enjoyed the benefits of a similar remediation programme, despite its explosive history.

If you leave Pontypridd on Llantrisant Road, slowly making your way up the hill, a left turn will eventually lead you to a single lane country road, which takes you even further to the top of the hill.

The solar farm on your right suggests this area of farmland is positive and forward-looking, but there could be different reasons behind a farmer using their land this way.

Just past the solar farm you might speed past an innocuous gate and some flimsy wire fencing on your right.

This nondescript entrance is the access point to the western portion of Maendy quarry.

The PCB chemical waste at Maendy Quarry near Pontypridd, from the former Monsanto factory in Newport in the 1970s, has never been properly remediated.The entrance to the western side of Maendy Quarry, which lacks any warning of the danger that lies beyond. Photo: Siriol Griffiths

Monsanto and others - including ICI and BP - used third parties to dump their harmful toxic waste here between 1966 and the end of 1970.

Internal documents from Monsanto show how after deciding to withdraw from the production of PCBs in Newport in 1970, contaminated waste from the site would be “sucked out into a waste tanker and the material taken to the Pontypridd site for disposal”.

Monsanto planned to monitor PCB levels in the area around the site at intervals of six months. And while their own numbers showed water in nearby streams had around 4 parts per billion (ppb) of PCBs (roughly twice their target, which was the water-soluble level), nearby farmers enlisted their own expert to take water and soil samples.

Concerns had been raised for years previously - a local vicar, the Reverend Arthur Williams, had been trying to draw the attention of local councillors and county councillors since at least 1967. In an interview with the BBC broadcaster, Vincent Kane, in 1973, Rev Williams explained how he first became concerned with toxic waste in the area:

The quarry at one time was a blazing inferno and fire brigades were called there to extinguish the blaze, drums were exploding thirty foot in the air.

Rev Williams said he was concerned about:

the contamination to the road and spillage of chemicals and tars, and oily substances on the roads, the obvious danger to the environment and the possible and potential danger to health.

Rev. Williams was being interviewed in the wake of a Sunday Times investigation which drew the quarry into the spotlight - using it as an example of dozens of other sites across the UK.

In the lead up to publication, journalists had met with Monsanto on numerous occasions to get their side of the story. An internal de-briefing memo from the company shows that the journalists had told them that the British chemical company, ICI, had even dumped explosives at the site above Pontypridd.

The PCB chemical waste at Maendy Quarry near Pontypridd, from the former Monsanto factory in Newport in the 1970s, has never been properly remediated.An internal Monsanto document from 1973 which mentions the tipping of explosives into Maendy Quarry by ICI

When farmers enlisted their own expert to examine the damage that had been done to the ground their livestock was on, their measurements of PCB were around 13-14ppm. parts per million.

This means that the land was contaminated to an extent seven million times higher than Monsanto’s internal targets.

The PCB chemical waste at Maendy Quarry near Pontypridd, from the former Monsanto factory in Newport in the 1970s, has never been properly remediated.Animals graze in a field next to the eastern Maendy Quarry. Photo: Siriol Griffiths

Pontypridd’s MP at the time, the late Brynmor John, argued with urgency in the House of Commons about the danger to public health, revealing that PCBs had been discovered in the milk of cows grazing nearby.

One of the features of PCBs which makes them so dangerous is that they degrade very slowly and are highly soluble in fat - meaning that they remain in the food chain once they are consumed.

This is why campaigners are so concerned about the discharge of PCB-contaminated water from the former Monsanto factory into the Severn which is permitted and continues today.

After the discovery of PCBs in cows’ milk near Maendy, one farmer was told that his farm was completely valueless as agricultural land - a story which may shine a light on the reasons behind the existence of the adjacent solar farm.

The PCB chemical waste at Maendy Quarry near Pontypridd, from the former Monsanto factory in Newport in the 1970s, has never been properly remediated.The entrance to the eastern Maendy Quarry is protected by large gates and a flimsy wire fence. There are no warnings at to the danger of the site except a Keep Out sign. Photo: Siriol Griffiths

Maendy Quarry remains unremediated to this day. However, Rhondda Cynon Taf County Borough Council gave planning permission to the present owners of the site, Veolia, to install a water treatment plant in both quarries in 2007, though work doesn’t seem to have taken place on this project yet.

In recent planning documents seen by The National, Veolia plans to pump polluted run-off from the western quarry through a new pipeline, underneath the public road, and into the eastern quarry.

The PCB chemical waste at Maendy Quarry near Pontypridd, from the former Monsanto factory in Newport in the 1970s, has never been properly remediated.A diagram from Monsanto's own internal documents showing that the west and east quarries were separate.

The eastern quarry was never officially used for toxic landfill. However, environmental campaigners accuse Monsanto’s waste disposal company Purle, who were later acquired by Veolia, of creating an acid tar lagoon in this quarry to dispose of toxic chemicals in.

You can read more about what acid tar lagoons are here. 

The PCB chemical waste at Maendy Quarry near Pontypridd, from the former Monsanto factory in Newport in the 1970s, has never been properly remediated.Views of the eastern side of Maendy Quarry from the road above. Photo: Siriol Griffiths

With no signs warning of the long term danger that lies beyond the flimsy fencing that surrounds this 15-acre toxic waste dump, questions remain about how safe the site really is, what kind of threat it still poses, and why the signage warning trespassers isn't more robust. 

And maybe think twice about picking the blackberries here.

The PCB chemical waste at Maendy Quarry near Pontypridd, from the former Monsanto factory in Newport in the 1970s, has never been properly remediated.Blackberries grow out of the Maendy Quarry site. Photo: Siriol Griffiths

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