ExxonMobil and Shell UK told incident was 'unacceptable'

Both petrochemical companies were also told by the Scottish Environment Protection Agency (SEPA) that “environmental compliance is non-negotiable”.

The watchdog said residents were badly affected by noise, vibration and black smoke over seven days in June, while unplanned flaring events in October 2017 and March 2018 are still being investigated.

SEPA chief executive, Terry A’Hearn, said: “The impact of unplanned flaring from Mossmorran last year was both preventable and unacceptable.

"We’re disappointed that both ExxonMobil Chemical and Shell UK caused an environmental impact on local communities which is why we’ve issued formal final warning letters, have commissioned a full review of environmental permits to operate and an enhanced programme of air quality monitoring.

“It’s clear that further actions are required by ExxonMobil and Shell UK to ensure the frequency and impact of flaring is reduced, but we’re encouraged by how both companies have responded, committing to respond positively to a strengthening of environmental controls."

Following an investigation by SEPA, which included formal statements from local residents, the regulator found that whilst flaring is an important safety feature in the event of a process fault, a series of maintenance failures led to elevated levels of unplanned flaring, in breach of environmental controls, between 12 and 18 June last year.

The incidents followed the breakdown of a condensate pump.

SEPA found residents were subject to considerable disturbance in their homes from noise, vibration and black smoke over the seven-day period, during which a total of 74 complaints were received by the agency.

Mr A’Hearn met senior ExxonMobil and Shell UK executives on site and said: “Every day, SEPA works to protect and enhance Scotland’s environment and compliance with Scotland’s environmental rules is simply non-negotiable.

"We’ll be working with the Health and Safety Executive, public health partners and communities to together both strengthen environmental controls and deliver powerful transparency over site operations.”

ExxonMobil operate the Fife Ethylene Plant (FEP) at Mossmorran, next door to Shell UK's NGL plant.

Between 2008 and 2016, there were 670 flaring incidents at the FEP and 753 at the NGL site.

James Glen, chair of the Mossmorran Action Group, said: "SEPA's report is very welcome, particularly the recognition that 'the impact of unplanned flaring from Mossmorran last year was both preventable and unacceptable'.

"SEPA is clear the flaring was down to a lack of maintenance by the operators which must raise questions about the overall safety of the plant."

He added: "SEPA's report shows communities were right to be fearful and angry about the irresponsible behaviour of the operators.

"We've now got the standard PR from ExxonMobil and Shell in response, but we've had that for years while emissions and safety at the plant have deteriorated.

"Thirty three years after the plant started flaring, SEPA still lacks the power and resources to assess and control all the environmental, health social impacts of the plant.

"We want to see an independent investigation backed up by Scottish Government action to ensure that communities receive proper protection."

Kirkcaldy and Cowdenbeath MP, Lesley Laird, said: “I welcome the findings of SEPA’s report and the action it has decided to take on this occasion.

“Communities, who for too long suffered from light and noise pollution associated with flaring at Mossmorran, will be relieved SEPA is finally taking appropriate measures and steps.

“However, this is only the start of a process to get to grips with these issues and, clearly, it’s what happens now to stop flaring episodes in future that will determine whether public confidence can improve.

“I have been working on this issue now since being elected and will be hosting a meeting tomorrow, the first to involve all key stakeholders together with cross-party and cross-community representation, and look forward to hearing first-hand the details of SEPA’s report.

“Clearly, there’s a lot of work to be done now and I hope this meeting will provide a first step to determining what can be achieved – and when.”

A statement from ExxonMobil said: "We apologise to the local community for the flaring in June last year which we recognise caused particular concern and inconvenience.

"We have cooperated fully with SEPA throughout its investigation and accept its findings.

"We have worked thoroughly to address the issues identified, consistent with our internal investigation.

"Following the events in June last year, we completed our own detailed investigation into the flaring and its impact on the community, and have already made a series of improvements to our maintenance processes, and to our flaring-related communications with the local community. We are also committed to work with SEPA on an enhanced programme of air quality monitoring.

"Flaring is safe and is used widely in petrochemical plants and refineries worldwide. Flares are designed to process hydrocarbons safely when production is interrupted.

"While the flare is a vital safety system for the plant, it is otherwise of no benefit to anyone including our operations because it impacts on production.

"We continue to invest in projects utilising the latest technologies and enhancements for the long-term future of the plant.

"Our team at FEP will continue to work with SEPA, other relevant agencies and the local community to monitor and minimise the impact of flaring."