Filtration upgrades at Perth’s Elizabeth Quay water park are complete, but there is no word on when the $13 million facility might reopen.

Water contamination forced the park to close just weeks after opening earlier this year.

A subsequent investigation by the Building Commission found a range of serious problems with plumbing at Elizabeth Quay.

The review found basic plumbing standards were not met in key facilities, some pipes had been installed sloping in the wrong direction, and plumbers had failed to put a vital non-return device, or backflow prevention device, in one of the water supply lines.

The lack of a non-return device meant that highly chlorinated water could have entered the main water supply to the park.

In another area, a sewer pipe was found to have been installed incorrectly, so that sewage was collecting in the pipe itself.

The Metropolitan Redevelopment Authority (MRA) told a Budget Estimates says upgrade works have been finished, and authorities are in the process of commissioning the new system.

No date has been set for reopening the park, and an announcement is not expected until after Health Department testing and monitoring of the new system.