WA water park health fear was known: Oppn

The WA opposition says the state government knew about water quality health concerns at Elizabeth Quay's water park before it opened.

The new Elizabeth Quay water playground, which has closed twice amid bacteria fears, may have been launched too soon and put the health of children at risk, the West Australian opposition says.

Labor's planning spokeswoman Rita Saffioti said there were water quality concerns a day before the BHP Billiton Water Park launched, followed by an emergency clean-up and certificate of clearance being issued just an hour before it opened last month.

The state government has confirmed a type of amoeba, thermophilic naegleria, and a variety of bacterium, pseudomonas aeruginosa, were detected in samples.

Opposition health spokesman Roger Cook said some children who played in the park had developed rashes and other symptoms, and said if they became ill from the playground, it was a serious concern.

"It certainly looks like public safety has taken a back seat to the government's concerns about having a party down here on the quay," he told reporters.

Labor will seek a response to its questions in parliament later on Wednesday.