The two councils have been at odds over the idea since 2017, when Central Otago district councillors spoke out strongly against the regional council's plan to put the disposal site on the straight, which begins at the Highlands Motorsport Park corner and continues to the Suncrest Orchard Jones family fruit stall.
Councillors said then the plan showed ''how little the ORC knows about our area'', and it was ''time to stand up to'' the ORC.
ORC director engineering, hazards and science Dr Gavin Palmer said in reply ORC staff had chosen the State Highway 6 site ''based on need and safety'', because spillage of stock truck effluent in the Kawarau Gorge was affecting road safety, the environment and human health.
Mr Cadogan told Cromwell Community Board members this week he was ''outraged'' to learn the regional council still favoured the Ripponvale straight site.
He said this ''defied belief'', as the road was a well-known, picturesque ''gateway to Central Otago and Queenstown'' that was much photographed by visitors.
The board and council have both voted to endorse the ''strongly worded email'' Mr Cadogan was sending ORC chairman Stephen Woodhead, ORC technical committee chairman Andrew Noone and Otago Regional Transport Committee chairman Trevor Kempton about the issue.
It would say that the ORC might be ''correct in law'' that it did not need district council permission to build the site where it wanted to, but ''it would be a terrible mistake [to build it without CODC approval] ... at every other level'', Mr Cadogan said.
The matter was also discussed at yesterday's full council meeting.
Roading committee chairman Dr Barrie Wills said it continued to be a ''no-brainer'' that the Ripponvale site was unsuitable.
The CODC favoured an alternative site near Tarras, he said.
Dr Wills said the ORC's technical committee would be discussing the issue today.
Cr Kempton said he was unable to comment about the issue until after today's committee meeting.
