A Coromandel dairy farmer has been fined $52,500 for illegally discharging effluent over a three-year period into a waterway that flows to Tairua Harbour.
Mark Fielden Ofsoske was convicted in the mid-1990s for similar offending.
The latest case, brought by the Waikato Regional Council, concerned events between May 2010 and May 2013 at Ofsoske's farm near Tairua.
Council staff inspected the farm on May 6 last year and found an effluent pond discharging dairy effluent directly into a waterway that ultimately led to Tairua Harbour.
Inquiries revealed that the farm had been following this practice since May 2010.
Convicting Ofsoske, Hamilton District Court Judge Melanie Harland said: "Given that he had previously been prosecuted for similar offending, albeit some time ago, I am satisfied that his approach was lax to the point of showing a real want of care."
Council investigations manager Patrick Lynch said it was rare for people to be prosecuted more than once under the Resource Management Act.
"We are using a number of regulatory tools, including prosecution, to change unacceptable behaviour," he said.
"I would have thought that being prosecuted is a huge learning experience for individuals and they would do whatever they could to avoid repeating the experience."