Local Government Magazine

COASTAL LANDFILL remediation case study

Steve Clarke and Anna Eisenhut from Waitaki District Council.
Historic coastal landfills pose a threat to our coastlines and Waitaki District Council is working to minimise this risk posed by three coastal land sites that are in danger of slipping into the sea. Co-authored by Anna Eisenhut and Steve Clarke, Waitaki District Council.

With two fly tipping (illegal dumping) sites on Beach Rd near Oamaru and the Hampden Closed landfill further south identified, the Waitaki District Council is proposing remediating the waste from these sites to the Waitaki District Council Palmerston Landfill which is due to close in August 2027 once the consent expires. 

The Beach Road Landfills were never specifically opened or approved by the council for use as landfill. Located along Beach Road, approximately three kilometres south of Oamaru, it is thought that these landfills were in “operation” between the 1950s to 1970s. 

These two unofficial landfill areas were investigated and partially remediated in 2017 after locals reported rubbish washing out onto the beach. Following these reports, approximately 60 tonnes of waste material was moved to Oamaru in 2017 and the areas were closed. The two Beach Road sites have a combined volume of approximately 5000 cubic metres remaining. 

The Hampden Closed Landfill is a former Municipal Solid Waste Landfill that was in operation from 1970 until 1996. In that time, it is estimated to have received around 30,000m3 of waste. 

The closed Hampden landfill has already been subject to onset coastal erosion exposing previously buried waste, with some waste washing out onto the beach. This necessitated remedial works in 2009 to prevent any further exposure of waste and contamination of the beach. 

Works included removing part of the buried waste and the placement of a rock rip rap slope extending from the toe of the landfill onto the beach. 

In finding a suitable solution to combat the effects of the coastal erosion, affected parties, being the Department of Conservation (DOC) and Kai Tahu Ki Otago (now Aukaha) were consulted. DOC raised concerns over geological features, cone-in-cone concretions and, along with KTKO, about the environmental impact of performing the remedial works. All works were executed in accordance with the associated conditions. 

During the remedial works buried waste was transferred from the Hampden Closed landfill to the Palmerston landfill. A total of 5090 cubic metres of compacted waste (including cap material) was transferred between September and December 2009. It is estimated that there is a remaining volume of around 25,000m3 to be removed. 

The council has removed part of the closed Hampden Landfill waste but with what we understand about coastal erosion and the expensive and destructive impacts of the waste falling into the sea, we need to take action now. We are working toward a longer-term solution for the remaining waste at all three sites and have learned from previous environmental events such as the Fox River landfill which saw thousands of kilograms of waste washed out to sea in 2019. We do not want something like this happening to our own coastline and local marine environment. 

The Waitaki District Council activated a project team in October 2022 on the back of a briefing by Project Manager, Steve Clarke. 

Called Project Reclaim, this team has seven key members: Roger Cook (Heritage, Environment and Regulatory Group Manager), Steve Clarke (Solid Waste Manager and Project Manager), Anna Eisenhut (Communications Specialist), Amelia Lines (Risk and Procurement Advisor), Lucianne White (Waste Minimisation Officer), Gareth Phillips (Senior Projects Engineer – Water Services) and Helen Ramsey from Morrison Low.

This project team is responsible for subtasks within the project and regularly collaborate and meet, sharing updates as the project progresses. It has been working alongside other team members from the council who are contributing to this project.

The request for proposal was released in January 2023. The following tenders briefing saw a total of 13 companies and 24 people in attendance over two days back in February that included site visits. We anticipate seeing some very high-quality bids come through. 

The project team has also commenced community engagement that has included meeting the residents of Falcon Street in Palmerston, which is where the entry to Palmerston Landfill is located, residents of Stafford Street in Hampden, and Ngai Tahu hapu – Te Runanga o Moeraki and Kati Huirapa Runaka ki Pukerteraki. Our next step is to host community engagement sessions for anyone in the wider community to connect with us and ask any questions.

Through our early community engagement, we have had several locals tell us they remember dumping rubbish at these sites with their families. They love the area they live in and understand the importance of these works. 

Palmerston Landfill consents expire in August 2027 and as there is no option to renew these consents, Council has a finite time in which to take the waste to Palmerston Landfill. The next closest landfill that would receive the waste is 300 kilometres away. 

The Waitaki District Council has been given approval from the Otago Regional Council to receive this waste at Palmerston Landfill.

Following due process, the successful bidder is expected to take possession of the sites from August 2023. LG

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