Consultants were working to determine whether more sites in the ACT would require testing for potentially toxic contamination left over from a now discontinued firefighting foam.
The deputy director of the Environment, Planning and Sustainable Development directorate, Geoffrey Rutledge, confirmed GHD Pty Ltd were in the process of identifying other sites which needed further investigation.
"Lessees will be made aware if testing is required," Mr Rutledge said.
The work follows the identification of per- and poly-fluoroalkyl substances, known as PFAS, at St Thomas Aquinas Primary School in Charnwood and the Ginninderra Christian Church. Both sites are adjacent to the former West Belconnen fire station site.
The chemicals, which have been linked to chronic diseases, were widely used in firefighting foams. The foams have not been used in the ACT since 2004.
In a report prepared for the directorate in July 2020, GHD concluded aqueous film-forming foams, which contained PFAS, were used on unsealed lands adjacent to the former West Belconnen fire station.
Last week, Associate Professor Peter Niven, a Canberra-based University of New South Wales PFAS expert, said the school's grounds should be shut until the complete site could be remediated. Professor Niven said windblown dust was increasingly considered a contamination risk.
But the ACT government has defended its advice, saying PFAS did not present a risk to human health unless it was absorbed through contaminated food or water.
"I advise that all areas within school play areas, that have been found to contain levels of PFAs above health-based guidelines, be cordoned off to prevent access by children until such time as remediation of these areas is completed," ACT chief health officer Dr Kerryn Coleman wrote in a letter to Catholic Education on August 18.
Dr Coleman said studies had shown PFAS had not posed a potential risk to human health even when it was present in the environment at elevated levels.
"Children would have to repeatedly eat large amounts of soil, without vomiting, to produce elevated levels of PFAs within their system. It is highly unlikely that a child's stomach would accommodate such material without vomiting or regurgitation occurring as a natural reaction," the letter, provided to the Sunday Canberra Times, said.
A post-election briefing to the Minister for Police and Emergency Services Mick Gentleman, released under freedom of information laws, said Rambol, an independent auditor, was reviewing all stages of the West Belconnen fire station site investigation.
The fire station was redeveloped into a childcare centre after the government sold the site in November 2016 for $2.1 million. An environmental management plan was in place to manage the "low levels" of contamination, a government spokesman said in November 2019.
At least 17 contaminated or potentially contaminated sites were on land controlled by the ACT government.
Eight sites operated by the Emergency Services Agency were found to be contaminated with PFAS at concentrations exceeding the recommended threshold.
The national Environmental Health Standing Committee recommends minimising exposure to PFAS.