Ramora UK and 6Alpha have carried out a controlled explosion of a Second World War bomb at the 576MW Gwynt y Môr offshore wind farm in Liverpool Bay, renews has reported.
RWE Innogy hired the firms to deal with the ordnance after three devices were discovered in January on the seabed at the project, eight miles off shore.
The companies applied a small amount of explosive charge to the bomb to make it safe at around midday today.
A 1000-metre exclusion zone is in place around the detonation for safety reasons.
The specialist bomb disposal companies will carry out further controlled explosions in the coming days to deal with the two remaining bombs, when tide and weather permit.
RWE Innogy UK Gwynt y Môr project director Toby Edmonds said: “As expected, the detonation had little impact on the surface of the sea.
“Work has now resumed in the offshore site while we wait for a further opportunity to carry out controlled explosions on the remaining UXOs.”
A Marine Licence and a European Protected Species Licence have been issued by Natural Resources Wales for the UXO removal works.