A Northern Victorian resident has told a court she fled her town in fear after hearing what she described as an “explosion” at the local canola oil processing factory earlier this year.

This week, Numurkah residents led by Kevin Green began a civil class action against GrainCorp in the Victorian Supreme Court, alleging the agribusiness giant expanded its production output at the expense of locals.

A middle-aged man with a moustache and a bald man walk side by side past a court building.

Numurkah resident Kevin Green (left) is a key witness in the legal action against GrainCorp. (ABC News)

On Thursday, mother of three Rebecca Abbey, who lives less than a kilometre from the Numurkah factory, took the stand in the Shepparton Courthouse.

She told the court she was woken by one of her daughters during the early hours of January 4 and they noticed an alert on the VicEmergency app “right near GrainCorp”.

“I sat with her in the lounge room, then, five to 10 minutes later, we heard a massive boom and the windows shook,” Ms Abbey said.

“I had to wake the kids up, get them out of bed and leave.

“I didn’t feel safe going back. We went for a drive out on the road and sat there for about an hour in the car. [I] didn’t want to go back anywhere near there.”

Resident Kerrie Wellman told the court she was also shaken up by the “explosion”.

“You know when you get a fright and you … feel like your heart has skipped a beat? That’s what it felt like when I first heard that explosion,” she told the court.

Ms Wellman, who has lived in the town for 42 years, said she found it difficult to get rest at night because her sleep was disrupted by noise at the factory.

Numurkah retiree Josephine Lowrie, who lives just doors from the factory, described hearing sirens and evacuations occur on multiple occasions at GrainCorp.

She recalled the fear that gripped her when alarms sounded at the factory during the night.

“Most of our anxiety in our area is we think if you [GrainCorp] blow, we blow up too,” Ms Lowrie told the court.

“I don’t want to lie in bed and blow up. I want to get in my car and take off.”A dark-haired man in silks enters a court building.

Barrister Roshan Chaile is representing GrainCorp. (ABC Shepparton: Andrew Mangelsdorf)

When GrainCorp’s barrister Roshan Chaile asked if she had complained to the company, Ms Lowrie said she had called on one occasion but did not end up taking the matter further.

Ms Lowrie told the court she had developed asthma and chest infections in the last several years and believed living near the factory had exacerbated that.

On cross-examination, the court heard she had no medical documents to show there was a causal link.

Mr Chaile also asked why she did not complain to the Environmental Protection Authority (EPA).

“I wouldn’t have even thought of the EPA,” Ms Lowrie said.

“People my age don’t even think of EPAs. We just deal with it.”

Thursday’s proceedings wrapped up the Supreme Court hearings in Shepparton.

Key witness Kevin Green will take the stand next week when the trial resumes.