Seismic activity stops geothermal drilling at Eden Project

Eden Geothermal confirmed it had halted geothermal drilling at its site in Cornwall late Wednesday evening

Operations have been stopped at a geothermal drilling site after seismic activity was detected.

Drilling began at the Eden Project in Cornwall in May 2021 in hopes of providing eco power and electricity to the Eden site and nearby industries.

Investigations confirmed the event on Wednesday was linked to the testing operations on site.

No damage was reported but operations were stopped so additional controls could be put in place.

Eden Geothermal have been drilling a three mile-deep (4.8km) borehole

The British Geological Survey reported two previous incidents of induced seismic activity at the geothermal site at Bodelva on 23 January and 5 March.

Eden Geothermal said in a statement: "We are aware that a small seismic event was felt and heard in the vicinity of the Eden Geothermal site shortly after 9.20pm this evening.

"An investigation and analysis of seismic monitoring data have confirmed that the event was linked to testing operations at Eden Geothermal."

It apologised for any disturbance caused.

One witness reported a feeling of "thunder".

A caller to BBC Radio Cornwall who gave his name as Reg said: "We live about two miles from Eden and at 9.20 last night we heard thunder in the distance, it lasted three or four seconds and then faded away."

Gus Grand from Eden Geothermal said workers were injecting water into the ground to test its permeability which triggered the tremor.

She said: "We're not drilling and we haven't been drilling since mid-November, we are testing at the moment which means we are injecting water into the ground to see how permeable it is and this is associated with tiny seismic activity.

"We've been doing it since January and we've had a lot of very small events which is great because it shows us where the permeability is in the rock so in the future we can generate electricity from it."

Ms Grand said people should not be worried by the tremor: "The event last night was just a little bit bigger than the others we've been having, the one last night was a 1.6 magnitude which is very common in the UK, we're not talking about anything that should cause anybody any worry which is why we put out a statement and stopped pumping for the moment."

The company said it would monitor the site for 24 hours and expect to start work again "cautiously with a very low pumping threshold".