A GOVERNMENT investigation into herbicide pollution in western Sydney that killed hundreds of trees and plants has narrowed the culprit down to a chemical compound produced at a factory in Girraween, near Blacktown.
The vegetation dieback, first noticed three months ago, has left a legacy of more than 200 dead trees that must now be removed by Holroyd Council.
Forensic testing on the dead plants has identified metsulfuron-methyl, a herbicide agent used to kill broadleaf plants, as the culprit.
The dead trees, backyard plants and vegetable patches are confined to a kilometre-wide radius around the herbicide factory operated by DuPont Australia.
The company confirmed the compound was an active ingredient in some herbicides made at the plant, but said a leak could not have caused the pollution.
''Yes, with the information available, this is still our belief,'' DuPont's Asia-Pacific crop protection business director, Mark Swinchatt, said.
''The symptoms observed and reported to us are not what we would expect to see from exposure to herbicides.''
Environmental consultant URS is preparing a report for the company on the vegetation dieback.
''We have conducted a thorough investigation at the facility and to our knowledge there have been no abnormal or unusual incidents or emissions at the plant,'' Mr Swinchatt said.
''DuPont's records and investigations have demonstrated that the filters on the stacks and outlets have been operating in a proper and efficient manner, minimising to the extent possible any emissions to atmosphere from those stacks.''
The Environment Protection Authority said the government investigation had not specifically connected the dead trees to the herbicide factory, though there is no other known cause.
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