MAYFIELD'S Koppers could face regulatory action, according to the state's environmental watchdog, after a "history of breaching environmental laws" and a fresh $15,000 fine.
The NSW Environment Protection Authority on Monday confirmed ti had fined Koppers Carbon Materials and Chemicals $15,000 over a Mayfield North ship transfer, which occurred in September.
The regulator said hot coal tar pitch was being loaded onto a ship when it came into contact with water, increasing pressure in the vessel's storage compartments.
Safety relief valves kicked in, venting "potentially harmful fumes into the atmosphere".
"The EPA's investigation found the loading happened too quickly, and that Koppers was aware of the issue after workers had previously stopped transferring the substances twice before the safety feature was activated," the EPA said in a statement.
"The incident resulted in an alleged breach of Kopper's environment protection licence."
EPA executive director of regulatory operations Jason Gordon said Koppers had a duty to ensure proper handling of materials like the coal tar pitch.
"Exposure to vapour from coal tar pitch is environmentally hazardous, and Koppers could have taken measures to prevent this incident from occurring," Mr Gordon said.
"We consider the incident was foreseeable and Koppers must prioritise compliance in its day-to-day operations. Extra care is needed when working on our waterways to protect our communities and sensitive marine habitats.
"Safety relief valves are designed for emergencies and their activation should be a last resort to prevent potential harm to the environment and public health."
The EPA noted it has issued 21 notices, official cautions and prosecutions in the Land and Environment Court in the past 12 years.
"These previous matters relate to odour complaints, air pollution and spilling coal tar pitch onto a wharf," it said in a statement.
"The Kopper's site has a history of breaching environmental laws, and the community has the right to expect better from its industrial neighbours," Mr Gordon said.
"We are monitoring operations closely and may consider other regulatory action if the company commits future alleged offences."
Newcastle-based Koppers Australian operations manager Nick Moretti said the company had already implemented additional measures to prevent pressure increases from triggering safety relief valves to release water and fumes during loading.
"We self-reported the incident to the EPA, conducted our own internal investigation and promptly implemented corrective actions," Mr Moretti said.
"The additional measures include Koppers' supervisors boarding the ship to also monitor pressure from within the ship's control room.
"Over the last 15 years, Koppers has spent more than $40 million on capital projects to improve the efficiency and environmental performance of the Mayfield plant. Our plant has had no odour complaints directly attributable to our operations since August 2022.
"Protecting the environment, our staff and the local community is our top priority."
