The state's environmental watchdog has stepped in to oversee the multi-million dollar clean-up of legacy toxins buried at the former Munmorah Power Station site.
The Environment Protection Authority contaminated land declaration comes after PFAS (Per-and Polyfluoroalkyl Substances) associated with a former firefighting training area as well as hydrocarbons were detected.
The scenario is similar to what occurred at the Williamtown RAAF base resulting from the use of PFAS-based firefighting foam over many years.
The Munmorah coal-fired power station was originally constructed in the 1960s and operated until 2010, with 2 units remaining on standby until 2012.
The twin 155-metre high chimney stacks were demolished in 2017, with the remainder of the plant demolished in 2018.
The site has been fenced off and inaccessible to the public since 2016, limiting potential contamination exposure.
The site's owner Generator Property Management [GPM] - a state-owned business - has been investigating future uses for the 700-hectare Munmorah site.
EPA executive director of regulatory operations Jason Gordon said the start of the rehabilitation process was a significant turning point in the site's future.
"Making this declaration allows us to regulate the ongoing management of the site and ensure all remediation efforts are carried out safely and in a timely manner," he said.
"This allows the site to eventually be redeveloped for another use, opening up opportunities for new jobs and investment in the local economy."
Fishing is banned within the power station's canals and water systems, but the EPA has advised that seafood from the Tuggerah Lakes system (Tuggerah Lake, Lake Munmorah and Budgewoi Lake) remains safe to eat as part of a balanced diet.
Species tested include sea mullet, yellowfin bream, dusky flathead, luderick, silver biddy, school prawns, eastern king prawns, and whiting.
Generator Property Management is responsible for the ongoing investigation and remediation of the contaminated areas.
An EPA accredited contaminated specialist, known as a site auditor, will oversee and review all works.
"GPM owns the impacted land and is required to keep locals and stakeholders up to date with the progress of its management plan," Mr Gordon said.
"The EPA will continue to work with GPM towards a safer and more sustainable environment for the Doyalson community."
In recent years, GPM has been committed to investigating PFAS and hydrocarbon contamination under the environment protection licence for the former Munmorah Power Station, and as part of the EPA's PFAS investigation program.
Pollution issues in other areas of the site, including the coal-ash repository will continue to be regulated under the existing environment protection licence.
The contamination notice and clean-up work will not impact on the construction of the Waratah Battery, which is also occurring on the footprint of the former power station.
The 850 megawatt battery is designed to act as a 'shock absorber' in the event of power surges caused by bushfires and lightning strikes.
It is due to be completed in 2025, before the earliest possible closure of the Eraring Power Station in August 2025.