A geneticist, Gemmell is part of a national group, led by the Institute of Environmental Science and Research Limited (ESR).
He said ESR had already done significant research into wastewater detection, but some people argued that New Zealand was already controlling Covid-19 and strengthening wastewater detection was unnecessary.
He strongly disagreed.
"Obviously, our situation in New Zealand is very privileged," compared with many other people overseas, he said.
However, circumstances could change "very fast", he warned.
"We can't take that freedom for granted."
"The question we have to ask ourselves is what are we prepared to do to keep ourselves in that privileged position."
Vaccination would make a big difference, but New Zealand had to protect itself long term against a virus still capable of killing people each year.
Major advances in genomic testing of coronavirus had taken place in New Zealand last year, all positive cases were now being sequenced and the value of doing so was more widely understood.
He urged similar advances in wastewater testing, particularly pumping in more Government resources to greatly speed up test results, and provide national coverage, including monitoring airports and MIQ facilities.
"Managing Covid is all about information," he said.
Late last year, ESR undertook an eight-week pilot testing programme involving many areas, including Dunedin, Invercargill and Queenstown.
