What lies beneath?

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    New River Estuary locals have concerns about chemical and bacterial contamination (inset) at the site of the old landfill. Photo: Laura Smith

    RESIDENTS concerned about the garbage state of Pleasure Bay Lagoon and the potential impacts on human health are wanting to know what is causing the bubbles and multi-coloured sheen at the old landfill site.

    Invercargill-based Labour List MP Liz Craig said she spoke to people, about 18 months ago, who shared concerns about the state of the New River Estuary reports which detailed expanding patches of mud and algae were not the only prompts.

    A year ago, about 50 people attended a public meeting to share those concerns. From that meeting, the New River Estuary Forum was formed to discuss what could be done to restore the estuary, and a prominent topic was the old landfill site at Pleasure Bay.

    “It was also the things we were seeing with our own eyes; the green scum floating on the water at Pleasure Bay, and the sticky knee-deep mud coating the estuary itself.”

    Dr Craig said they wrote to Environment Southland in August this year asking questions such as what the leachate was and how much of it was entering the water each year.

    “When I was last there I took some photos of the gas bubbling up through this shiny blue-orange liquid that was oozing out of the ground on the path overlooking Pleasure Bay. At low tide the same blue-orange liquid was seeping into the mud at the water’s edge.”

    Environment Southland (ES) chief executive Rob Phillips said they were aware of methane leaking into the estuary and several reports by ES had increased council’s knowledge of the estuary and the change in its environmental state.

    “The estuary suffers from the impacts of land reclamation, increased nutrients and sediments coming from the upper areas of the catchment. In addition, there are impacts from heavy metals entering the estuary via the old landfill and the stormwater network.”

    He said climate change also posed a “significant” risk to the estuary and public health due to the landfill’s coastal location.

    “We’ve identified this landfill as a priority site for detailed investigation to inform action.”

    ES would join the National Landfill Risk Assessment project, which was launched by Environment Minister Eugenie Sage in September, and would identify the risk from existing and historic landfills and what was needed to be done to adapt to the effects of climate change. “ES will join with two other councils in the pilot phases of the project. It is intended that the model and methodology produced from the project will be usable by all councils to risk screen and assess their own vulnerable landfills. Work to reduce the risk from vulnerable landfills could include protection from erosion, better containment of the site, or even removal of the contents of the landfill.”

    Invercargill City Council works and services group manager Cameron McIntosh said the old landfill site, which covers reclaimed and redeveloped land, extended from Victoria Ave to Bond St.

    It was the council’s job, under consent conditions, to monitor the landfill and estuary for contaminants, including methane.

    “The landfill was used for about 70 years, and was closed in 2004. For most of that time, it was the sole solid waste facility for the area and there were no restrictions on what could be disposed of at the site.”

    He said methane, nitrogen and bacterial contamination levels were monitored through water testing and observation but the methane produced was decreasing, and analysis of the lagoon water showed nitrogen and bacterial contamination levels were dropping.

    Council is planning strengthening work for the stopbanks around the estuary, which may present the opportunity for Council to include further works to protect the landfill from sea level rise.”

    He said Council welcomed the Ministry for the Environment’s plans to identify former landfills so “plans can be made for how to manage those sites in future”.

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