KOPPERS has been ordered to pay $82,500 for a coal tar pitch and unlicensed fume emissions at its Mayfield plant.
The company was convicted of three offences in the Land and Environment Court, and will pay the sum to Port Stephens Koala and Wildlife Preservation Society Ltd in lieu of a fine.
The company also had to pay the NSW Environment Protection Authority's costs.
The spill occurred after an October 2018 power outage, while the unlicenced fumes were released from a pitch storage system in May 2019 on consecutive days, which the EPA said led to "reports of health impacts on members of the local community".
Koppers attributed the leak to a faulty valve, which site manager Nick Moretti said at the time was "very rare". The company said it undertook upgrades, including installing pressure sensors on tanks, to limit the risk of a repeat of the problem.
The company pleaded guilty. Plant manager Nick Moretti said it regretted the incident, had installed new equipment and improved its systems to learn from the mistake.
"In consultation with the EPA, customers and the community, we continue to improve our performance and communication," Mr Moretti said.
"We strive to operate in a responsible manner to protect the environment, our staff and the local community."
The company, which employs 60 people at the Mayfield plant that has operated for more than 50 years, has spent $40 million on upgrading the site since 2008.
Correct Planning and Consultation for Mayfield convenor John L Hayes said the company's improvements, including a community reference panel that met quarterly, had been welcome.
"The outcome I think is that they are very much a better organised and controlled company than they were, and they're very conscious of doing what they need to do to comply with all the EPA rules concerning escape of gases and bad odours," Mr Hayes said.
"The $82,000 they've ben fined is a drop in the bucket compared to the millions they have spent [on upgrades]."
The court found the incidents caused harm and that the company could have taken measures to prevent it.
"Several reports of workers feeling unwell were received by the EPA at the time of the incidents, including one person who reported feeling like he was choking and needed a respirator for breathing difficulties," the EPA said in a statement.
"Another person suffered a sore throat and a headache lasting two days."
Acting director regulatory operations David Gathercole said the decision showed companies would be held accountable for breaches.
"The release of fumes such can have serious impacts on the health of people in surrounding communities, as well as on the environment," Mr Gathercole said.
"The EPA is continuing to closely monitor Koppers' operations. We've required significant improvements in performance through prevention notices, pollution reduction programs and licence changes, since this incident.
"The Koppers site has been the subject of numerous odour complaints over the years. We're working with the company to ensure necessary action to improve the functioning of the fume system at the plant is taken, to help reduce the potential for unlicensed air emissions."