A group of Red Hill residents are concerned a proposal for a major residential development in the area may be too close to an old contaminated dump site for housing.
Developer Hindmarsh is proposing to redevelop land bordering the Red Hill Nature Reserve on Kent Street, with at least 200 new units.
The site, Section 66, is also home to a Telstra facility and former Defence block, and it borders the old tip, a disposal site for asbestos and, residents believe, chemicals from the mint.
The company has three of the blocks, but if it also secures the old Telstra site and Defence block next door, the entire development could reach up to 550 units.
However, the entire development is contingent on a Territory Plan variation, as it would need to be rezoned for residential mixed use to allow it to go ahead.
Red Hill Regenerators' conservation officer and ecologist Dr Michael Mulvaney said they were worried about housing people on the block as it is directly downhill from the dump site.
He said historical reports indicated the dump was likely contaminated with heavy, persistent chemicals including carcinogenic substances as well as asbestos and heavy metals.
Dr Mulvaney said those chemicals, buried under metres of soil behind the proposed development site on Section 66, Deakin, have contaminated the soil and it was likely small seasonal water springs could also be contaminated.
"The site is downhill from this tip which has unstable and highly permeable soil on top, where we know there's been a history of fires and even 15 years ago sub-surface smouldering, so all of that we believe could pose risks if people were housed there," he said.
He was also worried about any potential risks associated with water flows from natural springs flowing down from the dump, as well as potentially contaminated soil at the old tip.
The tip site has been buried under metres of soil and trees have since grown, but was previously known as an illegal dumping ground after the tip closed, creating uncertainty about what exactly is under the surface.
"I'm concerned particularly if you have families living there, and kids who might be up on the block making cubby houses or digging in the soil and we don't know what they could be exposed to," he said.
Dr Mulvaney also was concerned part of the site had also been part of a larger critically endangered Yellow Box, Blakely's Red Gum Woodland across the nature reserve; one of few such populations around eastern Australia.
Hindmarsh chief executive Rowan Hindmarsh said the company would take any steps the government needed it to, such as an environmental impact statement, if required.
But he said it was still early days for the development, and the company had begun consultations to get a better idea of any concerns the community had, but it was a "very large site" and the entire proposal was "contingent on a range of factors".
"There have been community consultations we've had, and the community has been presented with all the information we have at this stage," he said.
Mr Mulvaney said the regenerators were open to more residential development, as long as it was appropriate, but that they were concerned about the cumulative impact of numerous proposals.
"This is just another in a long line of developments around the nature reserve, so we're also concerned that these things keep coming up individually and not looked at for the cumulative impacts," he said.
"It seems it's just up to a developer to apply for a variation and it's approved, so we really want more of a master plan approach.
"While we are open to the company opening consultation ahead of a development application, we would really like that to be government run or fully independent, because we don't know whether our concerns are actually being taken on."
While the Legislative Assembly last week approved an "integrated plan" for the area, it is unclear what shape such a plan would take, but despite the uncertainty Dr Mulvaney said he welcomed that news.