Keown said his fellow Christchurch City Councillors were not impressed by Ron McCandlish's presentation at a recent council meeting.
The city council was not taking McCandlish seriously, he said.
Keown believed Christchurch should be looking into alternative ways to treat water, other than chlorination. It has already cost the council to install temporary chlorination equipment, and is likely to cost more in the future.
The city should not "write off anything, ever", he said.
McCandlish, who runs the Gausstech company, said ionization was an effective and non-chemical water treatment solution.
It removed the health risks such as possible carcinogenic byproducts and corrosiveness that hyper chlorination provides, he said.
McCandlish said the American technology was proven through multiple studies.