Residents living close to the Corrib gas plant in north Mayo have expressed alarm over the intensity of gas flaring during New Year's Eve.
Shell E&P Ireland acknowledged on Friday evening that the flaring level was "exceptional".
“As the start up process continues ,there may be further intermittent flaring activity in the coming days,” it said.
“This will not be at the same level and we will take all measures to minimise any flaring occurrences,”it said.
The company had advised residents on Wednesday that flaring would take place “intermittently” as gas was brought from the field 83 km offshore to land.
Valves controlling the wells at sea were opened after final operating consent for the project was issued by Minister for Energy Alex White on December 29th.
Flaring or burning off of flammable gas is activated if there is a pressure rise within the plant, or a confirmed fire or gas release.
A YouTube film with John Egan of Shell E&P Ireland showing the flaring some minutes before it reached its peak, was removed from Youtube on Friday night.
In the video clip, Mr Egan was filmed against the backdrop of the flaring stack. He said it was 8pm on New Year’s Eve at Ballinaboy, and described the arrival of first gas as an “extraordinary sight” .
He said it was a “fantastic way to spend New Year’s Eve”.
The Corrib gas plant's emissions levels are governed by an integrated pollution prevention and control licence awarded to the project last October by the Environmental Protection Agency (EPA).
At the EPA oral hearing into its original IPPC licence, Corrib’s deputy operations manager said “a small amount of gas will be flared during a start-up until the export gas composition meets the required Bord Gais specification”.
He said volumes of gas flared and vented or released into the atmosphere are “kept as low as possible to minimise environmental impact”. Flaring worldwide is a significant contributor to greenhouse gas emissions.
Residents in the areas around Ballinaboy have witnessed flaring since November 2014, during testing of the system with gas from the existing network.
However, Aughoose farmer Gerry Bourke, who lives about a mile from the Ballinaboy plant, said that there was "nothing normal" about Thursday night's flaring, and said it was far more intensive and extensive than previously witnessed.
He said it “lit up the sky” and was accompanied by a “low loud rumble like a supersonic boom”.
Diane Taylor, who lives in Glengad, said she would not normally have had a view of the test flaring at the Ballinaboy stack from her home, but witnessed the New Year's Eve incident which she described as "frightening".
“The sky over Broadhaven Bay was pure orange, and it seemed as if thick smoke was billowing over the hill behind me,” she said. “It looked like the hill over by Pollathomas was on fire.
“It was about 8.15pm, and I opened the door and could smell smoke which would burn your nose, so I came right back inside,” Ms Taylor said. She estimated it lasted for about a half hour to 45 minutes.
Ms Taylor and neighbours subscribe to a text alert system, which Shell has invited residents to register for.
The company issued an alert on Wednesday which stated that “the valves which control the well out at the Corrib field have now been opened up” and “as part of normal start-up activities, please expect some flaring over the next 48 hours”.
Mr Bourke said he had also received this text, but it gave no indication of the extent.
“If this is normal, as Shell is saying, I don’t want to live like this,” he said.
Flaring continued on Friday. The EPA was unavailable for comment.