The Associate Minister for the Environment is investigating what can be done about a number of old landfills around the country that were not properly sealed, and are now vulnerable.

Photo: RNZ / Richard Tindiller

Eugenie Sage has been to the West Coast this weekend - assessing the massive clean-up of rubbish strewn for kilometres along the West Coast when flooding washed the remains of an old landfill down the Fox River.

While the river spreading the rubbish from the closed Fox Glacier Township Landfill has been successfully diverted, the massive clean up effort is far from over with Westland District Council saying rubbish had been sighted as far north as Ōkārito and south to Martins Bay in Fiordland.

Ms Sage said she is seeking information about the level of risk of similar landfills that could be exposed to flooding.

"I'll be asking the Ministry for the Environment for a better understanding of the extent of the risk and I would hope that councils around the country would be recognising the huge impact of what's happened when landfills get exposed to rivers and make sure that their landfills are well maintained."