South Taranaki iwi Ngāti Ruanui said it is alarming that health authorities have failed to test wastewater for Covid-19 outside of New Plymouth.
Two wastewater samples tested positive in New Plymouth last week, which the Ministry of Health said could be either recently recovered cases shedding the virus, or undetected cases in the community.
Latest wastewater test results from Saturday and Sunday, from six sites, have detected no further virus and daily tests will continue for the next week.
Ngāti Ruanui has backed a call from Māori Party co-leader Debbie Ngarewa-Packer for wastewater testing beyond the city.
Ngāti Ruanui kaiwhakahaere Rachel Rae said the iwi had serious concerns.
"Given the population of Taranaki is highly mobile throughout the region it is extremely unsettling to find out that no other regional wastewater systems are being monitored for the virus.
"Why are Hāwera, Pātea, Eltham, and Stratford wastewater plants not monitored? Is this a region of two halves?"
Taranaki DHB's Covid-19 incident management team controller Becky Jenkins said wastewater testing research is done by ESR and paid for by MBIE.
Jenkins said the DHB has no say in the research decisions but has been nevertheless been advocating for wastewater testing across the wider region.
"Taranaki DHB is working closely with the ministry's Covid-19 response team, and partaking in daily discussions about all aspects including wastewater and community Covid-19 testing.
"Following these results Taranaki DHB advocated for wider testing in the community and discussed these options with the Ministry, as it is important to have confidence that there is no active Covid-19 in our region."
The Ministry of Health said it had collected further test samples from sites around the region, but it is not clear where from.
Yesterday it said it had samples taken upstream of the wastewater testing point, but not in South Taranaki.
The mayor of South Taranaki, Phil Nixon, said he knew of no samples taken from the district's sewerage system but would welcome testing.
"I think it probably is worth doing to reassure the community if that's what they think needs to be done… Whilst it's in one part of the region it probably wouldn't be too bad an idea to check the other parts."
Nixon said many South Taranaki locals are often in New Plymouth.
"It would sound logical to me that we would test it because we do have a workforce that travels the region a lot."
But Nixon said he trusts both Taranaki District Health Board and the Ministry of Health to make the right call, given New Zealand's success against the pandemic.
"I think it needs them to consider it again. I'm not saying that they have to do it - but I certainly think it needs to be considered."
Becky Jenkins said the DHB and the ministry are urging anyone with symptoms, especially in New Plymouth, to get tested, as well as anyone in Taranaki who was recently in Australia.
Around 300 swabs were taken yesterday across the region, almost double the number on Sunday.
But Rachel Rae said any plan for Covid-19 testing of individuals "appears to be made up on the spot".
"We are also concerned about the use of primary health staff, our GP staff, to support the TDHB Covid testing centres. This is just shifting the burden of effort onto the smallest workforce who is already under strain and already spearheading the vaccination rollout."
Not much demand at iwi health centre
As yet the impact on the iwi's own health centre has been minimal.
Ngāti Ruanui Healthcare general manager Graham Young said the centre has continued to offer Covid-19 testing throughout the vaccination effort.
But since the positive wastewater tests in New Plymouth there have been just four swab tests at the clinic.
Nixon said at a time of heightened anxiety people need to get tested if they have any flu-like symptoms.
"It's easy enough to blame the authorities for things but I don't think we're having a lot of the public taking it seriously enough, and presenting themselves - people need to take some of their own responsibility."
Taranaki DHB has four community-based locations for Covid-19 testing in New Plymouth, Waitara, Hāwera and Ōpunakē.
Ngāti Ruanui and fellow provider Tui Ora also offer testing in New Plymouth and Hāwera respectively.
Local Democracy Reporting is a public interest news service supported by RNZ, the News Publishers' Association and NZ On Air.