Ipswich City Council says risks of Legionella spreading is very low after two workers were exposed to the bacteria in June.
It's understood the council workers came in contact with it while potting plants as part of the council's free plant program.
Ipswich's Interim Administrator Greg Chemello says it's wasn't the worst kind of Legionella.
"Legionaires disease there are two forms.
There's the nasty one people are thinking of - water off an air-conditioning system - where you have heard about stories in the past, in buildings or cruise ships etc.
That is not what this is!
If you go to any sort of nursery with any sort of potted plant there's an extremely low level of legionella or the chance of that throughout the potted mix".
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