Forum seeks urgent health risk assessment for estuary

Heavy metals and other toxins may be endangering public health at Invercargill’s New River Estuary, according to a monitoring group seeking an urgent health risk assessment.

Dissatisfied with information provided by Environment Southland the group has written to the medical officer of health requesting an assessment of the potential risk.

The forum, formed after a public meeting a year ago, includes Invercargill-based Labour list MP Dr Liz Craig and Dr Jane Kitson.

Leachate appeared to be entering the estuary from the old city landfill site, Craig said. People may not be fully aware of these risks when taking food like eels, flounder and shellfish from the estuary, or coming into contact with estuary sediment she said.

As an interim measure, the forum has asked for warning signs to be put around the estuary so people were aware of the potential risks.

The forum was concerned ES had been unable to provide further information on the amount and composition of leachate entering the estuary from the old site, the extent to which it was being retained in estuary sediments, and whether any public health assessments had been undertaken.

Environment Southland did have concerns about the estuary’s health, its chief executive Rob Phillips said, and the medical officer of health was the appropriate person to undertake any assessment of the risk to human health.

‘‘We look forward to the results of this assessment,’’ he said. ‘‘It will complement what we already know about the state of the estuary and the work we are doing to understand that environment.’’

ES received reports from the city council, which monitors discharges from the old landfill as part of its consent conditions, and had also commissioned several new reports about the estuary, which were currently being finalised.

ES had also joined the Government’s National Landfill Risk Assessment Project to identify risks from existing and historic landfills.

Invercargill City Council chief executive Clare Hadley said the council appreciated concerns that those who used the estuary ‘‘understand its health’’ and said the council would assist the medical officer of health ‘‘as appropriate’’.

The council undertook a snapshot of fish and shellfish in the estuary in late 2018 and this did not show a level of metals toxicity in breach of food standards.

As with so many things the situation of the old landfill had not

We look forward to the results of this assessment. Rob Phillips

developed overnight ‘‘nor will it be altered overnight’’.

Other factors contributing to the state of the estuary included the Oreti and Waihopai river catchments, a wastewater outfall and stormwater discharges.

Public Health South medical officer of health Dr Susan Jack said the testing of fish and cockles for heavy metals from the estuary in late 2018 indicated safe limits as per the Food Standard Australia and New Zealand.

"Therefore [we] do not have any current concerns from toxins being harmful to human health from fish and cockles."

But, given the group’s request, it would now plan on doing a public health risk assessment early next year, Dr Jack said.

Public Health South has not had any incidents of sickness brought to its attention arising from people’s engagement with the estuary.