Trility is owned by Hong Kong-based investment holding company Beijing Enterprises Water Group, which acquired it in 2018.
"I come to you with a heavy heart," Winters began, emphasising he was submitting as a private individual, not as a Bay of Plenty Regional councillor.
"Since 2013 I have stayed away from this organisation in terms of my opinion but there's some things I just cannot let go.
"I feel very strongly about this."
He said the proposal was "really biased" in favour of the council's preferred option to enter into a 10-year contract with Trility.
"There's an unconscious bias in this report to steer you to option one."
Winters said there were "far too many risks and far too many unanswered questions" with the proposal.
"Quite frankly it's horribly the wrong decision.
"This can be done in-house. This is your core business."
Councillor Reynold Macpherson also submitted against the proposal, sparking controversy about predetermination.
He laid out nine issues, including self-reliance for core infrastructure, undermining progress and impacts on accountability from outsourcing.
Much of his commentary quoted other people.
Out of 12 submitters at the hearing, just one was in favour of the partnership with the Trility consortium: John Pakes.
"The task before you is challenging. It is a challenge you must meet," Pakes said.
"You should bite the bullet and get on with it."
He said fears of foreign ownership of Trility were "xenophobic" and Trility would be motivated to not appear as a "communist bully".
Submitters' views
Don Atkinson
"To me [wastewater] is core business to the council. You should be retaining ownership of it."
John Gifford
"When you outsource things like public utilities, there are fish hooks. People interpret contracts differently. Disputes would arise."
Gerard Horgan
"There are too many unanswered questions to go ahead with option one. Contracting out is a solution in search of a problem. We're proposing to hand out a 10-year monopoly."
Dr Stuart Corson
"I cannot recall such a shallow proposal as this. Not by a country mile. It's devoid of detail and clouded with obfuscating irrelevancies. Isn't this your core business as a local government provider?"
Patricia Hosking
"Sewage - like water - is an essential service that should never be contracted out. Rotorua Lakes Council has written up the contract … and it's ready to sign. I see this as misleading the public."
