The Foy Group has defended its planned plastics-to-fuel factory at Hume in the face of health concerns, saying the minimal air emissions from the plant will be well under health limits.
In its revised environmental impact statement, released this week, Foy said a formal health assessment could only be done once the plant design was finalised.
But the company said this week the government had now requested a formal health impact assessment, and it was waiting for the terms of reference.
A spokesperson said the company had anticipated the assessment would be required at some stage.
"Foy is confident about its product and understands that the science is new and complex and requires accurate explanation and communication so that all are fully informed and assured of its merits and safety," the spokesperson said.
The company wants to build a factory at Hume to turn non-recyclable plastics - polyethylene, polypropylene and polystyrene - into petrol, diesel and LPG, using temperatures above 400C.
The plant will have tanks for up to 1810 kilolitres of diesel and petrol, plus 27 kilolitres of LPG. At full operation, it would receive six trucks of day of plastics, and send out six fuel tankers a day of fuel.
Foy is using new technology, invented by director Bevan Dooley, which it says addresses problems that have stopped others from commercialising plastics-to-fuel technology. Foy says its process removes ash, deals with hydrocarbon contaminants, removes impurities and uses waste gas for heating to burn off gas at a high enough temperature to destroy noxious compounds.
Foy has a factory at Berkeley Vale on the NSW central coast which re-refines "co-mingled" fuel back to diesel and petrol. It wants to turn that into a plastics-to-fuel factory of the kind proposed for Canberra, but the bid was rejected by the NSW Environment Protection Authority. The authority would not give reasons, when asked by Fairfax Media, beyond saying the proposal did not meet NSW's energy from waste policy.
Foy's ACT bid attracted a string of submissions from concerned residents and questions also from ACT government agencies.
ACT Health asked about expected emissions at the closest suburbs, Gilmore and Macarthur. Foy said its modelling suggested that at ground level the total-suspended particulate emissions in those suburbs would be 9.6 to 9.7 micrograms a cubic metre, which was well below the 90 micrograms a cubic metre allowed in the NSW guidelines.
The ACT had no air quality impact assessment standards of its own, so it had used NSW standards, as it had initially been asked to by the ACT authorities, Foy said.
ACT Health also asked for monitoring of nitrogen oxides and sulphur oxides in Gilmore and Macarthur - to which Foy said monitoring stations could be set up long-term if required.
Foy also provided a description of a plastics sorting machine that will remove PVC, sulphur and silicon-based polymers, rubber, batteries, electronic waste and other contaminants. It uses a sensor to detect the chemical composition of objects on a conveyor belt and sends a high-pressure air pulse to eject unwanted items.
Foy says harmful emissions are minimised with technology such as a "chilled vent condenser", which captures more hydrocarbon vapours than other cooling systems. Remaining gases are used as fuel.
"The levels of toxic compounds in the atmosphere surrounding the facility will be well below acceptable World Health Organisation levels as a result of the operation of the facility," it says. "Due to the mitigation measures taken the residual risk of the proposal causing levels of toxic compounds outside the acceptable limits is negligible."
The company acknowledges the health risk of the residue from its high-temperature conversion of plastics. But it says residues will be treated as contaminated waste, stored in sealed metal containers until cool, then disposed of.
It address fire concerns, acknowledging the risk to nearby properties and bush, but said a separate fire safety study would be done when the firm applied for building approval.
It proposes shut-down systems for fire, an "automatic plant deluge system", a 290,000 litre water storage tank and foam suppression.
It also acknowledges the risk from a bushfire threatening the factory, but says the plant would be at least 100 metres from grazing land which should limit damage from radiant heat and sprinklers would be set up on the perimeter fence directed 30 metres into the reserve.
The site is under a flight path, and Foy refers to a request from Canberra airport for detail on the height and heat from the emission plume at the factory. In its original response, Foy said there was no reliable method of calculating temperatures from the stack, so it used thermal imaging to measure a plume at its factory at Berkeley Vale. But given that factory is not converting plastics to fuel, the comparison has been deleted from the new environmental statement, with Foy simply saying that any flare would be below 20 metres and shrouded to reduce the chance of pilot distraction.
Foy, which owns mining exploration licences in Papua New Guinea, turned to its plastics-to-fuel idea in 2014.