The plaintiffs were oyster farmers. The oysters were believed to have been contaminated with a virus causing gastro-enteritis in humans. Three outbreaks of gastro-enteritis had been linked to the consumption of the oysters. The defendant, the Far North District Council, operated the Kawakawa sewerage reticulation and treatment plant. The plaintiffs alleged that in times of heavy rainfall, raw sewage was discharged from the Kawakawa sewerage reticulation and the treatment ponds at the plant overflowed. The plaintiffs said that when such discharges occurred the sewage made its way down the Kawakawa river to the oyster farms.
As a consequence of the outbreaks of gastro-enteritis, harvesting of oysters was only allowed on a limited basis. The plaintiffs had brought four causes of action in nuisance and negligence against the Council seeking to recover their corresponding financial losses.
The court examined, among others, the evidence regarding the discharge of sewage at the relevant times as well as other possible sources of contamination and concluded that the plaintiffs had failed to prove that, on the balance of probabilities, discharges of raw sewage from the sewerage reticulation or partially treated sewage from the treatment plant were the cause of any of the contamination events. The plaintiffs’ claims therefore failed.