The release of odourless gas into the national network last September, meaning 10,000 homes had to go without gas for days, was due to poor operating procedures at the Corrib gas refinery in Co Mayo.

A report by the Commission for Regulation of Utilities (CRU) concluded that the emergency on September 21, 2017, was due to a technical failure at the Shell E&P Ireland terminal at Bellanaboy. The CRU said it had followed up its findings with enforcement actions against both Shell and Gas Networks Ireland (GNI), which operates the national gas network.

As gas has no smell, odourant is added by Shell at its Bellanaboy facility so that people can identify any leaks.

The investigation found that the company’s operating procedures did not allow…