Work to clean up an historical landfill near Milford Sound — posing a “potential risk” to human health and the environment if it were to breach during more frequent weather events — is due to begin in April, the Department of Conservation says.
Upper Cleddau Flats landfill, known colloquially as Little Tahiti, extends inland from the Tutoko and Cleddau rivers, which both feed into Milford Sound.
Department of Conservation Te Anau operations manager John Lucas said investigations had uncovered contaminants such as asbestos at levels which posed a “potential risk to human health and the environment”.
The 8200 square metre landfill also contains waste material, rubbish, heavy metals, building materials, hydrocarbons like petroleum and general municipal waste.
Located 100m off State Highway 94, gravel was removed from the area to construct Milford Rd and the cavity was used as a landfill until the mid-1980s.
Lucas said “high-priority” remedial work was needed to address the risks.
“We are seeing more frequent high intensity rainfall events in Milford, like the 2020 floods, which did significant damage across DOC’s network of tracks in the region, including the Milford Track.”
An earlier weather event in 2019 breached a landfill in south Westland which spilled buried waste into the Fox River, sending it 21km down through Westland Tai Poutini National Park into the Tasman Sea – resulting in a massive clean-up.
“What happened at Fox River highlights the pressing need to address Little Tahiti as soon as possible to avoid a similar environmental incident,” Lucas said.
Remedial work would likely affect traffic on State Highway 94 with some traffic delays and increased truck movements.
It was expected to take two-and-a-half months.
The cost of the clean-up would be split evenly between the Department of Conservation and the Ministry for the Environment’s former Contaminated Sites Remediation Fund, which granted just over $2m to the project before it was closed.