COVID-19 sampling

As wastewater testing has been extended around New Zealand during the latest COVID-19 outbreak, smaller communities have become involved and Citycare Water’s Clutha team has played an important part in this early warning system.

“We started taking samples in late August in the towns of Milton and Balclutha which have more than 4,000 residents and since September 2 we’ve been doing daily sampling,” Citycare Water Clutha Treatment and Minor Capital Works Manager David Karrol says.

The work on behalf of the Clutha District Council involves collecting raw sewage samples at each location between 7-8am and then sending them to the Institute of Environmental Science and Research (ESR) in Porirua, he says.

The technique used is called grab sampling, with four samples taken 10 minutes apart then combined as one sample as representation of the location at that time.

“ESR sends us a chilly bin, containers and labels and we send them a 500-millilitre sample from each town which is collected by a courier and transported as dangerous goods,” David says.

The samples are tested for any traces of COVID-19.

ESR’s expansion of its wastewater testing in response to the recent outbreak of COVID-19 has seen samples collected from 148 locations covering an estimated 3.8 million people and 95 percent of the population connected to reticulated wastewater systems.

“The team in ESR’s Porirua laboratory and those helping with sampling and transportation around Aotearoa have pulled out all the stops to ensure there is unprecedented coverage of wastewater for testing,” says Dr Joanne Hewitt, Senior Scientist and project co-lead at ESR.

ESR Chief Scientist Brett Cowan says a unique study led by ESR with Watercare and the University of Auckland confirms the benefit of wastewater testing as part of New Zealand’s response to COVID-19, along with community testing and genome sequencing. For more information, click here.

Water treatment serviceperson Ross Pudney undertakes the COVID-19 sampling in Milton.