Waitaki District Council Commences Coastal Landfill Remediation

Published on 10 February 2023

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Coastal Waitaki is home to three historical coastal contaminated land sites which are in danger of slipping into the sea. Waitaki District Council is working responding and acting now to avoid a potential environmental disaster.

Waitaki District Council Solid Waste Manager, Steve Clarke said, “We cannot ignore this evolving issue and need to take a responsive approach to the situation. 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.”

There are three coastal contaminated land sites that are in danger of slipping into the sea. Two fly tipping (illegal dumping) sites on Beach Rd near Awamoa Rd, and the Hampden Closed landfill. The waste from these sites can be received at 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 Council for use as landfill. Located along Beach Road, approximately 3km south of Oamaru, it is thought that the landfills were in “operation” between the 1950’s to 1970’s.

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 Ōamaru in 2017 and the areas were closed. The two Beach Road sites have a combined volume of approximately 5,000m3 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 Hampden closed landfill site is located at the eastern end of Stafford Street, on the coastline beside the beach.

“Many locals remember dumping their rubbish at one of these sites, and while they have 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.” Said Steve Clarke.

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. The 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 in to combat the effects of the coastal erosion affected parties, being the Department of Conservation (DOC) and Kāi Tahu Ki Otago Limited (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 5,090m3 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.

Council is now working toward a longer-term solution for the remaining waste at all three sites.

Heritage, Environment and Regulatory Group Manager, Roger Cook said, “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.” 

Palmerston Landfill consents expire in August 2027 and there is not an option to renew these consents meaning Council has a finite time in which to take the waste to Palmerston Landfill. The next closest landfill that would receive the waste is the AB Lime landfill in Winton, Southland. Waitaki District Council has been given approval from the Otago Regional Council to receive this waste at Palmerston Landfill.

Request for Proposal (RFP) documentation has been published and following due process, the successful bidder is expected to take possession of the sites from August 2023.

ENDS