NSW authorities and the Department of Defence debated for years about whether to investigate potential contamination of waterways from toxic chemicals used at RAAF Williamtown.
Then on Friday they warned residents and suspended commercial fishing.
State agencies began letter-boxing residents living near the base and contacting 26 Tilligerry Creek oyster farmers, after issuing a notice late on Thursday that people should not drink bore water, or eat eggs from backyard chickens or fish caught nearby.
It follows the detection of chemicals from firefighting foam used at the base in the past around Tilligerry Creek and Fullerton Cove in the water and in elevated levels in fish.
Authorities admit the full extent of potential harmful health effects of the chemicals – perfluoro-octane sulfonate and perfluoro-octanoic acid – are unknown. Oyster farming and fishing in the area remain suspended.
‘‘The [Environment Protection Authority] refers to these as emerging contaminants because we don’t fully understand what the issue is, whether they are carcinogens or not,’’ EPA chief executive Barry Buffier said on Friday.
‘‘All the studies that have been done in relation to these chemicals have been done in animals – there haven’t been human studies.’’
But exactly when the chemicals were first detected outside the base remains unclear.
Mr Buffier said the EPA first learnt of the problem on August 18, when it received a draft report from Defence.
NSW authorities had urged the Commonwealth for the past few years to investigate, after Defence changed its policy on the use of the chemicals in 2008.
Like hundreds of others residents living in the RAAF base’s shadow, Lindsay Clout said he was horrified when he read about the pollution threat in Friday’s Newcastle Herald.
‘‘There’s been a lot of rumours about what sort of chemicals they have used up there over time,’’ said Mr Clout, a Fullerton Cove resident.
‘‘Today they have basically told us that we may have been drinking the stuff back in 2006. How can anyone feel safe after getting news like that?’’
Defence completed a preliminary assessment in 2013 before commissioning a further report.
‘‘The report came about because we had been asking the Commonwealth to do further studies on this to look at the possibility of offsite contamination,’’ Mr Buffier said.
Public notification of the contamination coincided with budget estimates sessions at NSW Parliament on Friday, where bureaucrats defended taking two weeks to notify the public after receiving the draft Defence report.
Department of Primary Industries director-general Scott Hansen said: ‘‘We didn’t hold this for any reason.’’
Advice had ‘‘gone out as soon as facts were known to be able to give a series of advice to residents without scaring them unnecessarily about potential impacts’’.
‘‘Two weeks after you knew about it?’’ Labor MP Penny Sharpe said.
‘‘Two weeks after it was first raised by the Department of Defence that there might have been an issue,’’ Mr Hansen said.
Asked by Labor MP Mick Veitch how long Defence had been ‘‘sitting on information’’, Department of Industry secretary Simon Smith said: ‘‘That’s a question for them.
‘‘We’ve been very pushy to try to get the information that we needed to be certain as to what action should be taken and we’ve taken it very quickly.’’
Port Stephens MP Kate Washington said she was appalled at how details of the pollution risk were passed to the community via media release on Thursday night.
‘‘The government has known about this for some time yet they chose to drop it in the middle of the night in a most alarmist and confronting way,’’ Ms Washington said.
‘‘There are a lot more questions than answers.’’
Ms Washington said she had sought an urgent briefing from Environment Protection Authority about the matter on Friday afternoon.
Sources said Defence representatives had urged that a public warning not be issued, during a phone hookup with various state agencies on Thursday before a statement was issued later that night.
Defence was also said to have objected to paying for the further sampling of fish and oysters that is now being conducted.
It did not respond to inquiries from the Newcastle Herald on Friday afternoon.
Mr Buffier told the estimates hearing Defence ‘‘were cautious about what would be the best way to put it into the public domain’’ but not ‘‘resistant’’.
He said the EPA had wanted Defence to undertake the studies of potential offsite contamination because the EPA had a ‘‘finite budget’’, the ‘‘polluter pays’’ and because ‘‘we don’t have the ability to regulate the Commonwealth on these matters’’.
Though it did not respond to questions, Defence issued a statement on Friday that said it was committed to working with state agencies.
‘‘The health and safety of people who reside near our bases and Defence personnel who work, or have worked, at these bases is a high priority for Defence,’’ it said.
A Hunter Water spokesman said two bores in the nearby Tomago sandbeds had been shut down as a precaution.
‘‘The bores have shut down for some time now. Our testing hasn’t shown any sign of contamination,’’ the spokesman said.
A NSW Health spokeswoman said expert advice was being provided about the potential health impacts to the community from potential exposure to environmental hazards.
‘‘NSW Health, often with the assistance of an external expert, assesses risks to health, identifies ways to reduce this risk in collaboration with other agencies, and contributes to the communication of this risk through providing information to affected individuals and medical practitioners,’’ she said.
All about Perfluorooctane sulfonate (PFOS) and Perfluorooctanoic acid (PFOA)
* Are fully fluorinated man-made compounds. They do not biodegrade and are persistent in the environment.
* They are mainly used in manufacturing and industrial industries as a surface-active agent in a wide range of products including coating additives, firefighting foams and cleaning products.
*According to the United States Environmental Protection Authority, the chemicals pose adverse effects on the environment and human health because of their ‘‘toxicity, mobility and bioaccumulation potential’’.
* Drinking water has been a major route of exposure in the US.
* Exposure can lead to the chemicals staying in the blood, kidney and liver for years.
*Studies in rats show the chemical is easily absorbed through the gastrointestinal tract.
*Studies in mice show the chemicals decrease the immune response of B-cells and T-cells, and induces tumours in the liver, pancrease and testicles.
*Other studies confirm the side effects include developmental delay and reproductive problems.
* PFOS and PFOA can be found in soil, air, and groundwater at contaminated sites.
* They have been detected in human blood within the general US population, and in wildlife.
* The US EPA has concluded exposure to the chemicals is widespread and chemical concentrations are higher in workers and individuals living near fluorochemical production facilities.
*PFOS has been shown to accumulate in fish tissue. Fish and fishery products seem to be one of the primary sources of human exposure in the US.
* Contaminated food and water, using commercial products and inhaling the chemicals are other ways people have been exposed.
For more information contact:
Environment Line 131 555 (who can direct your call).
For specific health inquiries –1300 066 055