The latest investigation into the lead contamination crisis at the stalled Perth Children’s Hospital has blamed a particular plumbing fixture for the problem.

Chief Health Officer Tarun Weeramanthri believes the fittings around at least 1200 brass thermostatic mixing valves (TMVs) are corroding and releasing lead.

The TMVs are used to combine hot and cold water before it comes out of mixer taps in the hospital.

Play Video The state government will have to replace the brass fittings responsible for the lead issue The West Australian Video The state government will have to replace the brass fittings responsible for the lead issue

“The TMV assembly boxes, situated next to approximately 1200 of the 1500 potable water outlets, are the likely source of a high proportion of the lead,” the report said.

He has recommended they be removed and was surprised previous reports for the Barnett and McGowan governments did not conclude the mixing valves were a major issue.

“It is notable that the comprehensive Jacobs Report, despite favouring the dezincification hypothesis, does not specifically mention TMV assembly boxes as a possible source of lead,” Professor Weeramanthri wrote.

“This is remarkable.”

He was also critical of builder John Holland, claiming the company did not provide details of a chlorination program to clean water when it was initially being released into the $1.2 billion hospital’s water system.

He described the lack of documentation about the chlorination as “striking”.

The report also ruled out the so-called “dead leg” section of piping as the current cause of continuing high lead levels.

In April, the McGowan Government “took control” of the hospital and accepted practical completion by John Holland, saying the company would still be liable for the costs of fixing the water issue.

Play Video The issue of lead in the water has still not been resolved The West Australian Video The issue of lead in the water has still not been resolved

But the hospital project, delayed by more than two years now, is no closer to being opened, is costing taxpayers about $6 million a month and looming as an expensive court battle between the Government and John Holland.

The West Australian revealed yesterday that a team of people have been tasked with turning taps on and off at the hospital.

The review consisted of analysis of prior reports, new data analysis, interviews with key stakeholders and a series of specially designated and targeted experiments.

The State Government has started developing a plan to remove the TMV assembly boxes.

Health Minister Roger Cook said that since coming to office, the McGowan Government had acted decisively to resolve the issues relating to lead in the new hospital’s water.

“We have taken control of the site by granting practical completion, identified the problem and found the main culprit,” he said.