A South Taranaki dairy farmer has been fined $50,000 after an effluent tank on his property was allowed to overflow for several months.
The Environment Court heard John Campbell Mead's spray irrigation pump failed, causing effluent to pool across paddocks on his Manaia farm from June to October last year.
The farmer, who had a previously unblemished record, was charged under the Resource Management Act with breaching consents for the discharge of contaminants.
Mr Mead said he had tried to correct the problem, but accepted full responsibility for the discharge.
The "ponding" of the effluent was caused by the poor management of a spray irrigation system, said Taranaki Regional Council resource management director Fred McLay.
It spread for 100m in a line between 5m and 15m wide and up to 30cm deep.
The Environment Court decision noted that a manual pump switch and a travelling irrigator could have been used during repairs to the system, but were not.
An inspection of the land in November 2015 found the problem had been fixed after the October visit led to an abatement notice being sent to the farmer.
The court issued its decision and a $50,000 fine to Mr Mead on Friday.
Taranaki Regional Council, which noted there was potential for the waste to leach into groundwater, said the sentence reflected the seriousness of his actions.