Greenpeace said in a statement it had tested a sample collected from the Gore town supply, which returned a result above 5mg/L nitrate (NO3-N), a level associated with an increased risk of preterm birth.
Above this level of nitrate, the New Zealand College of Midwives recommends pregnant people consider finding another source of water because of the increased risk of preterm birth.
The sample was collected on Wednesday and tested with an optical spectrometer, which is standard equipment for testing nitrate in the field, and followed the organisation's standard testing procedures which have been externally reviewed by GNS science.
While the township’s do-not-drink notice has been lifted, Greenpeace freshwater campaigner Will Appelbe says there was still a risk to public health.
Gore issued a do-not-drink notice last Friday after the town supply exceeded the maximum allowable value (MAV) of 11.3mg/l for nitrate. It recorded 11.4mg/l.
Greenpeace said the limit was set in the 1950s to avoid blue baby syndrome, but it did not take into account the more recent health science that has linked several health risks with long-term exposure to nitrate at levels below the current legal limits, including bowel cancer and preterm birth.
"We know the source of this pollution. It’s the overuse of synthetic nitrogen fertiliser in intensive dairy farming, led by Fonterra and their lobbyists at Federated Farmers."
Gore District Council critical services general manager Jason Domigan said the Water Services Act required all councils to provide water that was safe by meeting current drinking water standards.
That set the MAV of nitrate at 11.3mg/l. This is in line with World Health Organisation guidelines, an international standard, and has, in recent years, been through various levels of scrutiny through parliament and the national drinking water regulator Taumata Arowai.
He said since the sample on Friday, July 18 of 11.4mg/l, the council had seen a continuous decline in the nitrate concentrations at the East Gore Water Treatment Plant. Accredited laboratory results showed these were at 5.88mg/l at noon on Thursday.
"The council will continue to monitor through additional sampling over the coming weeks as we calibrate new nitrate probes installed at Coopers Well and the East Gore Water Treatment Plant." — APL
