• May 8, 2016

I was interested to have contact with and get information from campaigners in Wales concerned about nerve gas stored following WW2 at a quarry earmarked for a hydro-electric plant.

Their Freedom of Information request over possible contamination at the Glyn Rhonwy site near Llanberis was refused by the Ministry of Defence (MoD), who stated that:

“release of the information would enable ill-disposed persons or organisations to act against the national interest, and that therefore on balance the information should be withheld”.

After WW2 70,000 tabun nerve gas bombs captured from the Germans were brought to Glyn Rhonwy and stored temporarily, before being dumped in the Atlantic Ocean.

It’s thought that some UK chemical weapons stocks were also held there temporarily before being sent for similar deep sea disposal. We know from records that some disposals destined for the Atlantic went into inshore sites like Beaufort Dyke in the North Channel.

The whole period is shrouded in mystery not because of any intentional subterfuge but simply because in the haste to dispose of the highly dangerous weapons corners were cut and proper records not kept.

What we do know is that LCTs transported much material from shallow water ports in North Wales to Cairnrayan in SW Scotland for onward deepwater disposal. Some of these LCTs foundered themselves in the Irish Sea.

By the 1970s the sites in Wales were deemed clear and numerous plans have been drawn up for its redevelopment. Now Snowdonia Pump Hydro (SPH) want to create a 600 MWh pumped electricity storage facility on part of the sprawling site.

The Concerned About Glyn Rhonwy group reported their request for information to the MoD on their website and this was reported in media in N Wales (see below):

The group said: “Immediately after the war, because of its secure storage and rail connections, RAF Llanberis (Glyn Rhonwy) was temporarily used as a storage facility for 14,000 tons of bombs filled with tabun (a toxic nerve gas) which had been seized from German ammunition depots.

“It should be noted the RAF was unwilling to certify the quarries completely free of explosives, despite rendering safe each disposal area.

“A large scale cleanup was undertaken in the post-war years up until the mid 1970s, but it was clear material had been scattered both knowingly and unknowingly around the quarry complex.

“Little information was available to the public and the MoD were not forthcoming, but would not guarantee the site safe.

“Even at the time of the granting of planning permission for the smaller scheme in 2014, little information was available to the public to make a rational assessment of the risks associated with this ordnance.”

The British MOD reticence is unusual given that in the early 1990s after munitions including phosphorous based materials washed ashore in large quantities on beaches in Eastern Ireland, SW Scotland and the Isle of Man they released a plethora of information not only about the deep sea dumpsites but a large number of inshore sites such as Beaufort Dyke, the Holyhead Deep and the Hurd Deep in all approx 20 inshore disposals sites were indentified usually used to dispose of explosive ordnance although some like Beaufort have a full toxic mix and indeed the Hurd Deep has radioactively contaminated materials.

There is no mention in the Welsh group correspondence (we have studied to date) of any major initiative by the Welsh Environment Agency to tackle the concerns.

This contrasts strongly with the actions of SEPA in Scotland who have held the MODs ‘feet to the fire’ over contamination of places such as Dalgety in Fife (with radioactive material).

In the 1995 after a campaign by Celtic League about contamination around military bases and following pressure in Parliament the then Defence Secretary Michael Portillo ordered Land Quality Assessments at over 600 sites in use and disused in Britain and the North of Ireland. The programme is mentioned in the parliament answer several years later:


Indeed the MOD still have this programme in place see this link dated July 2012:


Celtic League would suggest that the Environment Agency in Wales take a leaf out of SEPA’s book and press the MOD to provide satisfactory public assurances.

In these dangerous times we can understand MOD reluctance to discover such lethal material but if we take the Nancekuke site in Cornwall (also a disused RAF base) where much British chemical weaponry was manufactured the MOD have given that site a clean bill of health – so what’s the difficulty in relations to N. Wales?

Image: Deep sea disposal was the preferred if crude method this illustration shows material being dumped by the US government. In addition to the Atlantic dumps the UK and their allies dumped UK coastal waters the English Channel (Hurd Deep), the Baltic Sea and there are vast dumps off Newfoundland,


Issued by: The Manx branch of the Celtic League

TEL: 01624 877918 or 07624 491609



The Celtic League established in 1961 has branches in the six Celtic Countries including our own Mannin branch. It promotes cooperation between the countries and campaigns on a range of political, cultural and environmental matters. It highlights human rights abuse, military activity and socio-economic issues

The link for the main web pages is below:


Mannin Branch Celtic League's photo.
About Author


0 0 votes
Article Rating
Notify of
Inline Feedbacks
View all comments
The Celtic League
Would love your thoughts, please comment.x