The Environment Court has ordered a Southland fertiliser company to stop dumping a dangerous contaminant in a gravel pit near Edendale.
Two people needed hospital treatment after being exposed to aluminium dross, left on the site by Taha Asia Pacific and Taha Fertiliser Industries.
A Southland Regional Council compliance officer visited the Coal Pit road site and saw two piles of gravel with shiny matter in them that turned out to contain the dross.
It had been dumped at the Crawford Enterprises pit to be used for roading.
Crawford's site manager says Taha assured him it was safe, but after two workers from a nearby contractor needed treatment for sore eyes and throats, the company asked Taha to remove the dross.
The Environment Court has ordered Taha to stop dumping the material there. The dross must be tested to ensure it is safe for removal.
Environment Southland acting compliance manager Graeme McKenzie said Taha must test the dross to find out how toxic it is, and where it should be moved.
"We cannot do anything further until we know what we're dealing with, if there is a high risk of contamination we don't want to move that to another location without knowing what it is that we're dealing with."
Mr McKenzie said he understood Taha had begun the testing process.