Silver Fern Farms fined $337k over potentially lethal ammonia leak 24 Feb, 2021 06:58 AM 4 minutes to read RNZ Silver Fern Farms has been fined $337,000 over an ammonia leak at its Hāwera plant that was potentially lethal to its staff, emergency services personnel and nearby residents. The February 2020 leak is also being described as likely the worst single-point freshwater pollution event in terms of fish killed in New Zealand history. In a departure from conventional practice, proceedings began today with a karakia from a Ngāti Ruanui kaumātua. The iwi is manu whenua of the Tawhiti Stream, which bore the brunt of the ammonia spill.