|A coastguard official monitors the Transocean Winner drilling rig off the coast of the Isle of Lewis, Scotland, after it ran aground in severe weather conditions, Tuesday Aug. 9, 2016. The oil rig, carrying 280 tonnes of diesel, broke free of its tug and ran aground on the remote Scottish island where it is being monitored by a counter-pollution team. (Andrew Milligan / PA via AP)|
The Transocean Winner was being towed when it broke free of its tug and ran aground on the Isle of Lewis on Monday.
The Maritime and Coastguard Agency says two fuel tanks on the rig have been breached.
Hugh Shaw, the government representative for maritime and salvage, said "we're probably talking about a maximum of 52 (metric) tons of diesel oil as the worst-case scenario." That's more than 50,000 liters (13,000 gallons).
Shaw told the BBC Thursday that any oil spill was a concern, "but this is extremely low-risk." He said there was no sign of oil on the ocean surface or coastline.