Lower Hutt Mayor David Ogden says Wellington Regional Council could sue itself over problems with a clean-up of the Waiwhetu Stream.
Two truckloads of soil from the banks of the stream were dumped in a landfill in Wainuiomata last month, before testing revealed the soil was heavily contaminated with lead. The disposal was revealed on Tuesday.
Contractors will begin moving the soil to Silverstream on Wednesday.
Mr Ogden says it's a serious case of contamination and every truckload of soil from the stream should have been tested.
He says there was a similar case in the 1990s when the council took legal action against itself as part of the resolution process.
