West Coast Regional Council hopes a substantial "dirty dairying" fine imposed on a Westland farming company serves as a warning shot to persistent polluters in the dairy industry.
Potae and van der Poel Limited was fined $120,000 in the Environment Court this week for illegal dairy effluent discharges on three of its seven farms at Whataroa.
The regional council prosecuted the company after finding overflowing effluent from ponds and irrigators on each of the three farms on at least 45 occasions in 2008.
Tributaries of the Whataroa River were also polluted.
The regional council says the offending was the worse it has ever seen.
Consents and compliance manager Colin Dall says the fine should serve as a deterrent to farmers who break the rules.
He says two more West Coast effluent discharge prosecutions are pending, although court dates have not been set.