Illegal dumpers are likely behind asbestos recently discovered at some Melbourne parks as authorities demand a council take action over the threat.
The Environment Protection Authority is investigating after suspected asbestos was found in six Melbourne parks in the Hobsons Bay City and Merri-bek council areas.
A seventh park - the PA Burns Reserve dog park at Altona - was flagged by a community member, prompting an inspection late on Saturday.
Inspectors looked at new mulch spread around toilet blocks at the PA Burns Reserve and found it contaminated with building waste, the environment authority said on Sunday.
The authority sent off six samples of potential asbestos while Hobsons Bay council was yet to disclose the source of the mulch.
The authority has slapped Hobsons Bay City Council with two remedial notices, demanding it conduct proactive inspections of more parks and gardens, and commission a hygienist to inspect all its parks that have received mulch in the past 18 months.
The work must be completed by May 10, with the authority also promising to review the council's mulch-related processes.
"(The authority) has requested all reports dating back to July 2021, from council, its staff, contractors and the general public in regard to asbestos containing materials found in mulch at or around Hobsons Bay City Council infrastructure," it said.
Investigations continue into material found at three other Altona North parks, with Hobsons Bay City Council also yet to supply the name of the mulch producer for GJ Hosken Reserve, an off-lead dog area.
Suspected asbestos found at GJ Hosken Reserve has been sent off for testing.
Asbestos fragments were found at Crofts Reserve and newer mulch there appeared more contaminated than older mulch, the authority said.
Bonded asbestos fragments found at PJ Lynch Reserve at Altona North were likely from illegal dumping, as was asbestos debris at Donald McLean Reserve at Spotswood.
"(The Environment Protection Authority's) investigations are showing much of the material found at these sites may be a result of illegal dumping," the authority said in a statement on Sunday.
"When determining if a case is likely to be illegal dumping, officers look at the size and placement of the material.
"When suspected asbestos pieces are larger in size than the standard size mulch, it is unlikely the asbestos has been through the mulching process."
Inspectors sent off another three pieces of potential asbestos - believed to be from a building source rather than mulch - from Shore Reserve at Pascoe Vale South.
Merri-bek Council was remediating Hosken Reserve at North Coburg after asbestos was found during the construction of a park at the reserve in January.
The asbestos there was believed to be from historic building material, the environment authority said.
Merri-bek Council confirmed the asbestos-contaminated soil was found within the area closed for the major upgrade works.
It was professionally removed but more asbestos-contaminated soil was discovered recently, again within the construction site area closed for upgrade works.
The newly located contaminated soil is being removed.
Premier Jacinta Allan said she understood the public's concern and it was important authorities gave the community clear regular updates.
"The EPA have rigorous powers, they are undertaking those investigations right now (and) we'll be releasing the results of those investigations to ensure they can provide the accurate, important information communities are seeking," she told reporters on Sunday.
Opposition Leader John Pesutto called for a taskforce to audit which parks were susceptible to asbestos dumping and absorption.
“(The government's) approach over the last 48 hours has been completely chaotic," he said.
Hobsons Bay City Council says sections of Crofts Reserve, Hosken Reserve and Lynch Reserve, all in Altona North, will be closed until further notice.
So far, the material contained to contain asbestos has contained bonded asbestos rather than the more dangerous friable asbestos.
PARKS UNDER INVESTIGATION:
* PA Burns Reserve, Altona North
* GJ Hosken Reserve, Altona North
* Crofts Reserve, Altona North
* PJ Lynch Reserve, Altona North
* Donald McLean Reserve, Spotswood
* Hosken Reserve, North Coburg
* Shore Reserve, Pascoe Vale South
Source: Environment Protection Authority