Researchers from the Nelson-based Cawthron Institute have been conducting ongoing research into the same problem in the Waikato River.

Environmental toxicologist Dr Louis Tremblay said New Zealand’s wastewater issue was not as severe as the UK's, where the ratio of wastewater to water was about 50 per cent.
“Our towns are quite coastal, so most of our discharge is into the ocean, although there are a few catchments like the Mataura River in Southland, which Gore for example feeds into.”