The government is assessing a funding application from the Westland District Council to help with the clean-up of an old Fox Glacier landfill exposed by flooding.
The National Party said the local council cannot manage the clean-up by itself and the government needs to step in and provide financial support.
Associate Environment Minister Eugenie Sage said the Department of Conservation and the Environment Ministry, among others, have been supporting the council, which has applied for funding of $700,000.
Old rubbish has been spewing out of the Fox Glacier dump and down the Fox River since flooding last month.
The Westland District Council last week said it needs government help with a conservative estimate of the clean-up bill at $1 million. The council said although it will continue to support clean-up efforts, it will only do so within its financial capabilities.
National's environment spokesperson, Scott Simpson, agrees the local council cannot do the clean-up by itself, and said financial support from the government was needed.
"This is an old landfill with all kinds of materials that were just thrown into holes in the ground from 20, 30, 40, 50 years ago and it's now washing down the Fox River into the West Coast marine environment and then eventually washing up onto West Coast beaches - that's an environmental disaster by any measure."
Mr Simpson said future floods would send more rubbish out into the natural environment if nothing concrete was done.