The house at 37 Goulburn Place, Macquarie was bulldozed 20 months ago and taken off the register of Canberra properties impacted by Mr Fluffy loose-fill asbestos.

But bonded asbestos was uncovered on the block this week when the ACT Asbestos Taskforce tried to dig a drainage channel to allow pools of water to drain.

Neighbour Greg Wilson emailed the taskforce after Sunday's deluge, concerned about the large amount of water streaming into his yard from the cleared Fluffy block.

The water flooded his side yard, dragging mud and muck through the back garden before draining into an oval behind the property.

The taskforce got back to him on Monday, saying they would send someone out to have a look, and on Tuesday workers showed up to fix the problem.

However they uncovered bonded asbestos in the rear corner of the block, which required a licensed assessor to remove.

Mr Wilson's wife Melissa was warned not to go out in the backyard while the work was ongoing.

Mrs Wilson said the worker who knocked on her door told her there were "bits" of asbestos in the water.

The exchange alarmed Mrs Wilson, whose great-uncle died from mesothelioma 15 years ago, because she was not told what sort of asbestos was found.

The Wilsons were finally told on Wednesday that it was not loose-fill asbestos and that the bonded asbestos had been removed.

But given the block would be sold on Thursday, Mr Wilson was concerned who would foot the bill if contaminants were found to have washed through his yard.

"If something is found, who is liable," Mr Wilson said.

EPSDD's deputy director-general for sustainability and the built environment Geoffrey Rutledge confirmed the site was now clear of asbestos and the new owners would be informed of the removal.

"Potential purchasers of remediated Mr Fluffy blocks can have confidence that blocks have had thorough soil testing undertaken by a licensed asbestos assessor or soil validator to test the demolition zone for loose fill asbestos fibres and confirm the site is suitable for residential reuse," Mr Rutledge said.

Mr Rutledge said they would not undertake testing in the Wilsons' backyard, as no loose-fill asbestos had been found on the block.

The Wilsons decided to share their concerns publicly, after it was revealed another Mr Fluffy block sold at auction had been contaminated with bonded and loose-fill asbestos.

The Steve and Jeffcott families have been left with mounting costs after asbestos-ridden remnants of old house were found on their $1.6 million block when the builder was preparing to lay the slab.

Fairfax Media has learnt of at least one former Fluffy homeowner, who after seeing the standard of the clean-up, did not opt to buy their block back.

However Sydney University Emeritus Professor Bruce Armstrong, who was one of the consultants engaged by the Australian National University to look into the health effects of Mr Fluffy, said people should exercise "normal, sensible caution" with the blocks.

"There is asbestos in the air you and I breathe every day, we've all got a decent load of asbestos in our lungs but the risk at those kind of background levels is low," Professor Armstrong said.

"The people who are at high risk of course are the people who actually worked with the raw asbestos, either mining it or milling it or using it to manufacture asbestos products. That's where all the mesotheliomas have occurred.

"We do know that for example when people who worked in the asbestos industry brought home the asbestos in their clothes and in their hair or whatever, there is an increased risk to the people who lived with them but in other circumstances of exposure in normal homes, except for the specific instance of the Mr Fluffy houses where we have seen evidence of an increased risk for men, it's been hard to demonstrate any risk in any of those other circumstances."