The airport was one of three where residues of the banned chemical perfluorooctane sulfonate (PFOS) were found in firefighting foam.
More seriously, an Environmental Protection Authority (EPA) investigation found the chemical in storage at six other New Zealand airports, as well as in equipment owned by two companies servicing airports, three sites controlled by a major oil company, in two tug boats and at a tyre company.
EPA chief executive Allan Freeth said his officials were "very surprised" to find the banned foams, but they had been secured against use at all sites and posed no risk to the public.
No operators had been prosecuted because enforcement and compliance action had been successful.
Queenstown Airport acting general manager communications and community Naomi Lindsay said low levels of residual contamination were found in two of the airport's four fire trucks last August.
It had since been working to arrange "an appropriate cleaning location, set up and disposal requirements, as this is not something we have in place as a smaller airport".
"We anticipate it will be a matter of weeks now for this to be in place."
Of the two trucks, one was a back-up vehicle and the other was decommissioned but remained on site. Neither had been used in any capacity since August.
"Our main two trucks are not contaminated, so there's been no impact to our readiness or operations."
Dr Freeth said the lower levels of PFOS in firefighting foam found at some sites was probably the result of contamination from previous use of PFOS foams.
"I want to stress we found no intentional non-compliance.
"We concluded it was highly likely all the banned foam we identified had been imported before 2006, when it was legal.
"There is, however, no excuse when businesses that are part of the professional firefighting sector do not keep up-to-date with law changes in their industry."
All operators were now following the EPA's directions and complying with storage and labelling laws.
The importation of PFOS foams was banned in 2006, and in 2011 all PFOS products were banned and strict controls placed on their storage and disposal.
Firefighting foams containing PFOS were widely used from the 1960s to the 1990s,
as the most effective means of extinguishing highly volatile, liquid fuel fires.
