In expert evidence to the NSW Environmental Protection Authority, which is assessing the application, former US EPA air enforcement division director, Bruce Buckheit argued the proposal was against the public interest.

"If the exemption is granted to January 2027 as requested, it is a near certainty that this facility will continue unabated NOx emissions until whenever the operator decides to retire it," he said.

Mr Buckheit said Delta's approach was "contrary to the intent" of the law, and raised concern the exemption could set a precedent for other power stations to make the same argument.

"Vales Point has now received the benefit of two such five-year extensions and employs the same NOx control strategies (i.e. none) as in 2011 (and perhaps in 1974)," he said.

"In seeking to continue unabated NOx emissions past the 50th birthday of the plant Delta misses the 'clear signal that outdated plant and equipment (including pollution control technology) will need to be progressively upgraded'."

Following a concerted community campaign, the NSW EPA recently opened the proposal for consultation ahead of its decision.

It comes as a NSW parliamentary committee last week called for updated laws on air pollution, to bring the state's controls in line with international and World Health Organization standards.

The committee reviewing the Clean Air Bill, noted: "It is time that NSW's comparatively outdated and relaxed exceedance limits are tightened to reduce harmful impacts to NSW residents' health."

Environmental Justice Australia, the Australian Conservation Foundation and Future Sooner are among groups urging the EPA to refuse the application.

"Every Australian deserves clean air and to live free from the dangerous health effects of toxic pollution," Environmental Justice Australia Lawyer Charley Brumby-Rendell said.

"Power station operators must take all reasonable steps to minimise the risk of harm to people and the environment and comply with existing state air pollution laws, which are already significantly weaker than WHO guidelines."

Australian Conservation Foundation campaigner Suzanne Harter said older power stations like Vales Point needed to be carefully policed to ensure they did not damage global and local environments.

"This power station should not be exempt from complying with pollution rules," she said.

In a statement Delta Electricity rejected the groups' claims.

Spokesman Steve Gurney said Vales Point operated in accordance with strict environmental licence conditions and with diligent oversight by the EPA.

'This is a collection of anti-coal activists with one objective, to shut down coal fired power stations', he said.

He said EPA analysis consistently showed that air quality on the Central Coast and Lake Macquarie was amongst the best in NSW.

"It also concludes that 'levels of nitrogen dioxide, sulfur dioxide and carbon monoxide easily meet National Standards'. Specifically, monitoring has shown that NO2 concentrations were either very good or good at all monitoring sites at all times.

IN THE NEWS:

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: