ExxonMobil Ltd say a new pump is being fitted this evening and flaring at their Mossmorran plant should cease on Thursday. 

The burning of excess gas at their Fife Ethylene Plant (FEP) started up again on Saturday with the large orange flames visible for miles around. 

ExxonMobil, who were issued with a final warning last month over flaring at the site, blamed a "mechanical issue" with a pump for the latest incident, which saw emergency services called to the site on Saturday evening. 

This afternoon, the firm gave an update that said maintenance teams, assisted by specialist pump suppliers, were "working round the clock to resume normal operations" at the plant. 

The pump will be installed this evening "and the current outlook is elevated flaring will cease on Thursday".

Sonia Bingham, the plant manager, said: “The focus of my dedicated team at FEP is to return this pump to service as soon as possible and I reassure everyone we are working tirelessly to resolve this issue as quickly and diligently as possible.

“We are doing everything we can to minimise the size of the flare and any disturbance to the local community.

“Nobody wants flaring, but it is necessary when a production issue occurs, and is permitted by SEPA subject to strict regulation.”

ExxonMobil said flare was an "essential part of the plant’s safety systems, which is designed specifically to handle gas when there is an interruption to the production process, and there is no danger to local communities or employees".

They added: "We are working to minimise any impact of flaring by minimising the amount of gas being flared, optimising steam levels to the flare to ensure clean burning while reducing noise, and monitoring noise levels within the local community.

"Ethylene production is a complex industrial process – there are over 200 pumps at FEP – and the work to bring the new pump into operation will involve (amongst other things) cooling and drying it with nitrogen to remove any moisture, before chilling it to around minus 40C – a process that can take many hours.

"This is an essential part of the recommissioning process.

"We continue to work closely with SEPA as we resolve the issue. We apologise to local communities for any disturbance and are in contact with local agencies and community groups to ensure local residents are kept informed."