The Waitaki District Council wants to avoid the potential environmental disaster of three former coastal dumping sites slipping into the sea.

The Waitaki District Council wants to avoid the potential environmental disaster of three former coastal dumping sites slipping into the sea.

The historical contaminated land sites - two illegal dumping sites on Beach Rd between Ōamaru and Kakanui, and the closed Hampden landfill - were all coastal, and the situation needed a “responsive approach”, council solid waste manager Steve Clarke said.

Request for Proposal (RFP) documentation had been published, meaning contractors were being sought to bid for the work. Following due process, the successful company was

expected to take possession of the sites from August 2023. 

Proposals needed to also detail the approach to the required upgrades at the Palmerston Landfill and the operation of the landfill until its closure in August 2027, Steve said.

The assessment of proposals would consider a wide range of factors including the bidders’ proposed approaches, prices, and environmental and social outcomes.

“We cannot ignore this evolving issue . . . We have learned from previous environmental disasters such as the Fox River landfill, which saw thousands of tonnes of waste washed out to sea in 2019. We do not want something like this happening to our important coastline,” he said.

The Beach Rd landfills were never specifically opened or approved by the council for use as landfill. Located approximately 3km south of Oamaru, it is thought the landfills were used between the 1950s and 1970s.

“Many locals remember dumping their rubbish at one of these sites, and while they’ve said they never felt good about it, it was just the done thing. We know better now and are striving toward fixing the past and working toward a better future,” Steve said.

The two unofficial landfill areas were investigated and partially remediated in 2017 after locals reported rubbish washing out onto the beach. 

Approximately 60 tonnes of waste material was moved to Ōamaru in 2017 and the areas closed. The two Beach Rd sites have a combined volume of approximately 5,000m3 remaining.

The closed Hampden landfill was a municipal solid waste landfill between 1970 and 1996, at the eastern end of Stafford St. In that time, it was estimated to have received around 30,000m3 of waste. 

The waste from all three sites can be received at the council-owned Palmerston Landfill, which is due to close in August 2027, once its consent expires, meaning the council had a finite time to take the waste there. The next closest landfill is Winton.

The Hampden landfill has already suffered some coastal erosion, with previously buried waste washing onto the beach. Remedial work was carried out in 2009 to prevent any further exposure of waste and contamination of the beach.

Part of the buried waste was removed and the placement of a riprap rock slope extending from the toe of the landfill onto the beach.

During the remedial works, buried waste was transferred from the Hampden closed landfill to the Palmerston landfill. It is estimated that there is a remaining volume of around 25,000m3 to be removed.