SEPA has had an influx of complaints as ExxonMobil restarted a petrochemical plant in Fife on Thursday night.
The plant was shut down a year ago after complaints of persistent flaring
Many local residents took to social media to complain on Thursday night, with some reporting that the flames were visible from as far away as Edinburgh.
ExxonMobil appologised for the intrusion and said the elevated flare was being used as part of the restart work.
A spokesman said the process of restarting the plant was "safe and controlled", adding: "Our team are working to reduce both the size and duration of the flare."
He continued: "We apologise to communities for any concern that we may have caused."
The flaring occured as the plant is being restarted In recent years local residents have complained of repeated unscheduled flaring incidents leading to noise, disturbed sleep, light pollution and vibration to houses.
The process of flaring involves burning off gas that cannot be processed. The site, which is shared by ExxonMobil Chemical Ltd and Shell Fife NGL, is used to produce ethylene.
Although the technique is legally permitted, it causes significant light and noise pollution which the operator is obliged to minimise.
the Scottish Environment protection Agency tweeted the below tweet after an inlux of complaints.
The Scottish Environment Protection Agency (Sepa) said in a post on social media that it was "receiving a high volume of calls" about the flaring, adding that it was "working hard to address the root-causes of 'unacceptable flaring', making flaring an exception rather than the routine".
It added that it was requiring the operator to make changes which would make a "real difference to local communities".