"That places everybody, including staff, under suspicion, and my being full and frank about my conversation has alleviated that. It also avoids another $20,000 code of conduct complaint. I'm naturally disappointed, but I appreciate that I placed Mayor Annette in a difficult position that she had to address," he said.
Asked why he thought the document was going to be made public, he said he had never been comfortable that the evaluation of options for upgrading the plant had been robust enough.
"Specifically for the last year, I have sought to have a more in-depth analysis done on the option of pre-treating the wet industries at source and thereby reducing the biological load on the plant.
"It's been a view from some that this action would lower costs substantially."
Mr Vinsen said he wanted to be sure that this pre-treatment was not the most cost-effective option, which is the view of Cardno BTO, the specialist company the council engaged to investigate problems at the plant.
"My insistence resulted in the meeting of August 30 last year, where five options I put forward, along with another from [then] Councillor Michael Laws, were reported on by Cardno BTO and [engineering consulting company] AECOM.
"After that meeting I was concerned that both Cardno and AECOM's analysis was both not exhaustive enough and not properly documented. I took the view that a third opinion was required to be sure that we were doing the right thing."
He said management eventually agreed, and it was his understanding that council would get a third opinion of both the chosen Cardno design and another design, and these would be presented at the May 1 workshop. "The findings of that evaluation would then be made public at a meeting that was scheduled for May 19. However, [council lawyers] Kensington Swan advised that the findings would be better to remain in confidence, at least in the meantime," Mr Vinsen said.
The council has filed proceedings against engineering consulting company MWH Global, the company the council hired to oversee the building of the treatment plant in 2005 and commissioned in 2007. But he is adamant the information divulged could not in any way compromise the council's legal position.
"Kensington Swan say it 'may' do. They reason that they would rather choose the best time to reveal findings. I take the view that it's very important the public see that council is not hiding anything in this process.
"We cannot let ourselves be blinkered by a court case in how we rectify the plant. Every part of the rectification process should be done in public, and I will continue to advocate this.
"My council focus may change slightly, but I remain a loyal and supportive member of this administration."
